yahoo is a good place to start, espn is good. if you want a competitive league you might try joining an existing league that someone has an opening where 1 owner isn't coming back. the biggest problems with the popular sites is many owners will draft 15 teams then abandon most. teams and leagues are always been advertised, look around and find a good league. do a couple mock drafts before the real thing. Your catcher advice was incorrect. there will be plenty of draft guides and info on who should get drafted where coming out in the next month.
When asking for roster advice in these pages, remember there are thousands of different sets of league rules & many different active roster settings. If you want the best replies, be sure to include your leagues particulars in the original post