restrict who can connect to database engine via ssms

I have a very simple DB set up in SQL Server 2005. I only use my databases via SSMS running queries on them there. I do not use these DB's with any interfaces or applications of any sort. What I need to do is lockout all access to those databases with the exception of user accounts I allow. To keep it as simple as possible, is there a place I can just create users and grant them access thereby denying access to anyone else who tries to connect to the database engine?