For posting: - invitations to games (you can also use the New Game menu or go straight to the Chess Invitation) - information about upcoming tournaments - discussion of games (please limit this to completed games or discussion on how a game has arrived at a certain position ... speculation on who has an advantage or the benefits of potential moves is not permitted) - links to interesting related sites (non-promotional)
Scid is an applications program in which internet datatbases can be downloaded, PGN for instance. Scid then converts the PGN file into a "scid" file that allow the moves to be replayed on their chess board. There are search engines to find the games you want from the database by ECO, or a given position, or a particular player, etc...