Add user to sql server with the required permission

Question

In my sql server express 2008 r2 i have about 15 login account. Now i want some about 5 users have full permission while some other 5 users with limited access to some database, and other users only read permission. In future i may add other users also. So i was thinking of doing it in simple way than giving permission for every user as it requires giving permission to each database every time a new user is created. So can i create a set of rules or group and then add a new user to that group or rules? Do i have any kind of facility in sql server which will make this happen?