Building an Opening Book with chesstools
When you run the MICS client, you can tell it which .book file to load with the -b argument. So if you run ' -b tal_tactical' the program will load '' from the 'books' folder and hand it over to your ai. Simple. So where do .book files come from?
If you're running MICC, that means you've already installed chesstools. If not, you can easy_install it ("easy_install chesstools" - only works if you have setuptools) or just download it here.
Building an opening book is easy, but it doesn't come out of thin air. First, get a bunch of pgn-formatted source games and put them all in the same directory. It's also ok to just have one huge .pgn file. is a pretty good place to start looking, but is impractical because you have to grab games one by one unless you have a premium membership. Smaller sites like pgn mentor are more useful for this sort of thing. Anyway, once your collection is ready, just hit the command line:
>> buildchessbook
where is the file or directory of pgn-formatted games?

what will you call this opening book database?

which color should i use?
"white", "black", "both", or "player" (to select player by name)

ok, which player?
Now you have an opening book called "", and it can play just about as well as Bobby Fischer, himself. Stick it in your "books" folder, and you're ready to hit the server!