Where should I look for a list of tournaments in which new players can participate? I know that many players want to play real matches, but don't know how and where. Also provide list for online tournaments.
For european events - http://chess-calendar.eu/ Includes non-FIDE tournaments.
For online, redhotpawn.com has tournaments (although you need to pay a yearly subscription (around 50 USD) to be able to participate on them, otherwise you can just play informal games). These are mostly email games.
Also chess.com has tournaments, you also need to be a subscriber there (here you can play both realtime & by email).
chesscube site also conducting various online tournaments with different time limits.
For US tournaments (both rated and unrated ) the most updated site: