1) Cricsim is a Cricket Simulator. It is awesome. Can be downloaded off the net.
Basically, it works on batting and bowling averages. You select a playing XI, and the game simulates the match with commentary. It has an in-built stat tracker which records all runs and wickets and averages and such. Apparently, it also has something inbuilt that takes form into consideration, so a player scoring a lot of runs will continue to do so.
2) In the PC Cricsim Leagues, you just sign up as a player, hope you get selected by a team (Otherwise you spend the time honing your skills with the n00b XI until the next season) and then hope you get selected in the first XI by the Team Manager. Generally, if you are an active poster you'll make the team. If your whole team is very active, you'll probably have to perform well to make the XI. There are FC and OD leagues, and 6 teams in all, and it is buckets of fun.