This subject has been extensively covered by Alexander Bergengrün and others. Perhaps a few odd bits and pieces from the archive of the Livonian Governor General are worth noting:
On 16 December 1700 Erik Dahlbergh wrote to Olof Hermelin, who was working on a refutation of the Russian complaints against Sweden, i.e. the reasons for attacking Narva. One of the items on the agenda was the supposed maltreatment of the Great Embassy when it passed through Livonia in 1697, notably the fact that Dahlbergh did not acknowledge the presence of the Czar and failed to show him the necessary courtesy. This was a point Dahlbergh found hard to accept. As far as he had been informed Peter was travelling incognito and had threatened to execute anyone who failed to keep his secret. How could the Russians possibly complain about this, the Governor General wrote. The Czar had made a point of staying among the servants and the "riffraff". Yes, Peter had even served wine to Lefort, the nominal head of the Embassy. When Lefort and Captain Johan Brask were playing card the Czar had stood behind Brask's chair just like another servant, Dahlbergh wrote to Hermelin. The Russian manifesto deserved a very harsh reply as their complaints were totally unfounded. They know no honour, the enraged Dahlbergh exclaimed.
Source: LVVA, fond 7349, op. 1, vol. 72
In LVVA, fond 7439, op. 2, vol. 285 one can find something as exotic as menues from September 1696. It lists about a dozen dishes for each day. Among them are such delicacies as "laxvälling (salmon gruel), "kabeljo i huuset" (literally: dried cod in the house), "två gäddor med rovor i huuset" (two pikes with turnips in the house) and "förlorade ägg med corinther" (poached eggs with corinth raisins).
It's obvious that these menues were written for the higher officials as they end with a list of food to be served if something extra was needed - on Monday "fresh tongues of oxen" and on Friday "an English pudding". The menues are followed by lists of food for the "commoners" - very few dishes each day, mostly grain and fish.
In 1896 Friedrich Bienemann jr published a collection of documents concerning the siege of Dorpat (Tartu) in 1656. Among them are a series of letters from Governor Lars Fleming to Magnus Gabriel de la Gardie, the Governor General of Livonia. They are dated 3 April, 14 May, 28 May, 28 May, 8 June, 18 June, 9 July, 15 July, 28 July, 27 October and 10 November. Rainer Fagerlund mentions a few others: Fleming to de la Gardie 4 June, 21 June and 11 July. To this list of letters in Stockholm and Riga can be added the following, preserved among the Malmberg papers in Uppsala University Library: Fleming to de la Gardie 25 June, 19 July and 23 July. In the first of these Fleming reports that many peasants have run away and are plundering the estates of the nobility. He also reports problems with the guns - some are without carriages. In the letter dated 19 July Fleming gives details about the approaching Russians. They had crossed the border during the night between the 15th and 16th. Some units had headed directly for Neuhausen. If Neuhausen fell, Fleming wrote, the enemy would soon attack Dorpat. Reinforcements were urgently needed. In the last of the three letters, dated 23 July, Governor Fleming informs de la Gardie that he has not received any recent reports from Neuhausen. In a hastily written note at the end of the letter he writes that a detachment of cavalry just had returned. They had seem many fires in the direction of Neuhausen. The castle was supposedly still holding (apparently incorrect), because the enemy had not yet been able to bring up the heavy guns.
Uppsala University Library, Dorpat-Rigasamlingen, vol. 2 and 3 (subsequently rearranged and renamed Livonica)
Briefe und Aktenstücke zur Geschichte der Verteidigung und Kapitulation Dorpats 1656 // Mittheilungen aus der livländischen Geschichte. - 16:2. - Riga, 1896. P. 515-606
Fagerlund, Rainer, Kriget i Östersjöprovinserna 1655-1661. - Stockholm, 1979
I recently added to my collection of Polish books:
1. Urzędnicy Wielkiego Księstwa Litewskiego: spisy. Tom III. - Warszawa, 2015. This is a series which began appearing in 2003. It lists the names of officials on various levels, in this case for the Duchy of Samogitia. These books are invaluable for anyone who tries to identify the Polish and Lithuanian nobles who appear in Swedish documents from the GNW period. Previous volumes have covered the voivodeships of Vilnius, Trakai and Smolensk.
2. Pabich, Lukasz: Bitwa pod Koniecpolem 21 listopada 1708. - Zabrze, 2014. About the battle between forces loyal to Stanislaw Leszczynski and those Polish and Lithuanian forces which refused to accept him as king. The unprinted sources are Polish-Lithuanian only, but the printed ones more diverse (unfortunately in some cases they are of a highly dubious nature).
3. Płowy, Damian: Poniec 7 XI 1704. - Zabrze, 2013
4. Płowy, Damian: Od Ponieca do Bełcza Wielkiego. - Zabrze, 2015. Both books are about the final stages of the 1704 campaign. Both volumes are quite thin, but the author appears to have consulted many archival sources both in Poland and abroad (though not in Sweden).
5. Wimmer, Jan: Polska-Szwecja : konflikty zbrojne w XVI-XVIII wieku. - Oświęcim, 2013. A summary of the events during the many wars between Sweden and Poland by the veteran historian, who as far back as 1956 published a large volume about the GNW (Wojsko Rzeczypospolitej w dobie wojny północnej 1700-1717).
On 22 July 1700 Erik Dahlbergh wrote to Charles XII, informing him that General Vellingk "who had been standing here so long without doing anything explicit against the enemy" despite every possible preparation having been made for a crossing of the Düna. Now the Saxons had been reinforced and the on the 17th they had crossed the river at Pröbstingshoff (Sprēstiņi). Vellingk had moved towards the enemy the following day and on the 21st attempted an attack, but finding the Saxon position too strong he soon retreated. Dahlbergh was very unhappy, telling the King that he saw no other means of defending Riga than asking Vellingk for reinforcements. On 27 July Vellingk wrote to the Chancery in Stockholm, stating that Vellingk had retreated "in confusion" with the cavalry and 1,500 foot, but the rest of the infantry and some cavalry had managed to enter Riga.
A list preserved elesewhere gives detailed information about the reinforcements received - about 5 100 officers, non-commissioned officers and soldiers from the Finnish infantry regiments (Close to 700 from the Tavastehus infantry, close to 1,000 from the Åbo infantry, about 900 from the Savolax infantry, about the same from the Björneborg infantry, about 700 from the Vyborg infantry and above 800 from the Nyland infantry).
LVVA, fond 7349, op. 1, vol. 72
Krigsarkivet, Krigshandlingar. Stora nordiska kriget. Avd. 19, vol. 1
It's sometimes stated that the French ambassador Guiscard was present in Riga during the Düna crossing on 9 July 1701. I am not where this story comes from, but it was used to great effect by Frans G. Bengtsson in his vivid description of the event. Unfortunately it's entirely fictitious. Guiscard was not permitted to accompany the army when it marsched southwards in June and instead went to Reval (Tallinn). In late July (Guiscard says the 29th, Dahlbergh in one letter writes the 27th and in another the 29th) Guiscard came to Riga, despite Governor General Dahlbergh having informed him of the King's wish that the foreign diplomats should remain in Reval. The French ambassador, Dahlbergh writes, had many ideas for restoring the peace, but they were all dependent upon the King respecting the neutrality of the Polish Republic. The Dutch ambassador was also in Riga, impatiently requesting an audience with Charles.
LVVA, fond 7349, op. 1, vol. 73
Brulin, H., Sverige och Frankrike under nordiska kriget... - Upsala, 1905
Below is a list of letters sent by Governor General Dahlbergh on a fairly typical day (20 July 1701):
1. Order to Lt Col. Zöge to hand over equipment from the stores in Dorpat to Lt. Col. Wrangel and Lt. Col. Hastfehr.
2. Letter to Inspector Järmestedt about an offer of 50 oak planks made by the Town Councillor Rennenkampf.
3. Letter to the Town Council of Riga about quarters for Col. Brakel and his unit.
4. To Paul von Strokirch about provisions.
5. To the district bailiff Falckenhagen about going to Kokenhusen to make an inventory.
6. Permission for Cornelius de Geus to load his ship and sail.
7. To district bailiff Falckenhagen.
8. To Lt. Col. Zöge about the printed account of His Majesty’s great victory.
9. Reply to Col. Brakel’s memorial.
10. To Lt. Field Marshal De la Gardie regarding Wrangel’s battalion of militia.
11. To Inspector Järmerstädt about masts for England and Holland.
12. Passport for Mohrman to go to Neustädtchen.
13. To Inspector Järmerstädt about two merchants from Lübeck.
Source: LVVA, fond 7349, op. 1, vol. 53