Text help!

I hope this is okay, if not then delete.

I'm having some problems with text. I was hoping someone could tell me what text looks best in an icon where I want to be able to read it, but isn't too big. As far as size is concerned I'm thinking something like 5-7.  I just can't find anything that looks good.

In fact if anyone has a complete text guide that would be lovely too! 

Please and thank you! =)