This is a small start at having a links section here. The following are sites I've found very helpful:
Bones' Combat Guild to Might & Magic VI
Although this site is expressly for MM6, the game rules probably apply to 7 and 8 as well. Very, very comprehensive analysis of combat from the game designers' standpoint as applied to tactics the players should use. You can also find out whether it will be helpful to add to your stats or not. Incidentally, you can "see" Bones in MM8 in Lord Brinne's tomb: All those visitors there are real fans from the original message boards at New World Computing (as was the late Lord Brinne).
Castle Gobs
Sections for all the Might & Magic games from 6 through 9, with an introduction to the fan-created game of MM-tribute (Ribannah, the site creator, is one of the designers behind the fan-created MM-tribute game). Special focus on obtaining the highest possible scores from the games. You can also "see" Ribannah in MM8 in Lord Brinne's tomb.
Flamestryke's Games Pages
Flamestryke has near-comprehensive coverage for Might & Magic VII, VIII, & IX, including regional and dungeon maps.
Enroth in 5 Days
A not yet finished walthru for a fast game of MM6 - which does it without giving away an exact path to follow. Besides the MM6 walkthru, though, this site has game editors available for download for MM6, 7, and 8.
The Erathian Liberation Party
Home of the Taverns Message Board for all Might & Magics - these people specialize in technical help if you can't get your game to work properly, but will also help you with quest questions (Be aware that they will NOT help with questions you can look up in the game manual - even if you don't have a manual. In D&D terms, they are LAWFUL GOOD in all caps and view the absence of a manual as evidence of a pirated game). Even if you have a question about a Might & Magic game that predates #6, they can probably answer it for you. Their MM9 website is now the home of the official patch, as well as their own homemade patch to fix some still-existing bugs in that game - plus they are working on yet another addition to it for us fans, as well as the fan-created MM-tribute game.