Full-Text Search on multiple tables

I have a query that searches for Forum Posts containing the search terms provided by the user.
I have enabled my MESSAGE field in the 'POSTS' table for full-text index and the search will work if I dont need to reference any values from any other tables, but the problem is, I need to bring in a number of other fields from different tables when my result is returned to the user, for example, the POSTS table has a USERID field that relates to the Users table, to identify who made the post. From this I want to return things like the USERNAME associated with each post returned from the search, where they live etc.
Is there any way this can be done bearing in mind that I am using a "FROM FREETEXTTABLE (Posts, Message, 'search term string here')" approach?
In the past, I would simply have a number of joins to each table I needed other info from, but now I'm using Full-Text I don't know how to join, or even if I can, the other tables for the additional information?

Any help would be much appreciated.

Thanks in advance.