Huge DB and Log files

Dear friends,

I've installed the SQL Server Forum on June 13th. Today, 15 days later, the SQL Server DB is 254,13Mb and the Log file is 235,56 Mb. The Database file size is 18,56Mb. We have a total of 415 members and about 20,000 messages.

Is that correct? Aren't the files too big? Am I going to experience instability on the forum's performance?

How do I do the shrinkdatabase thing? I mean: I logged into my server, right-clicked on the forum database and there was this All Tasks - Shrink DB. Is that it? What options should I use?

It says:

Space allocated: 368Mb
Space free: 33,16Mb (9%)

Shrink action
Maximum free space in files after shrinking:  (I have to choose a %)

There's a option of Moving pages to beginning of file before shrinking. Should I check it?

It also gives me the option of shrinking individual files from the DB. What about this?

Thank you!