I've just finished writing a 44-page e-book that provides a comprehensive step-by-step checklist for filing trademark registration applications through the USPTO website. It also includes a wealth of additional information about the trademark selection process, and some other stuff you need to know before filing for trademark registration.
Check it out, it's free from TrademarkIntel: Guide to Filing Trademark Registration Applications.
Not comfortable doing it yourself? Don't have the time? Rather have a professional do it for you? That's understandable, and that's what I do for a living.