Hello Matthew. Welcome to Geni!
How did you come to own your books? <Jealous!>
There is another thread where people have been adding internet resources as they've discovered them. There are gems. http://www.geni.com/discussions/80238
Also, we have another user here, Private User, who I have come to view as my research guru.
Again, welcome to the family.
I use a lot of different sources. For my father's mother's father's side of the family, I've been very spoiled because he was from the Boston upper-class and, as a result, his genealogy had been done to death right up through recent generations. It's not really exaggeration to say that I was handed a stack of documentation and pedigree charts at birth. So...they're not really my fun ones to track down. I like the hunt. :)
For the rest of my family, where I have to start from scratch, I use a variety of sources. The best place to begin is with oral interviews. My grandmother had an incredible mind for remembering names, dates, and places, so she gave me my best leads. I also used things like her personal phone book, paperwork she'd held on to, her government documents (like her British and Bahamian passports), etc. to track down leads. I can't imagine starting without those types of interviews and resources if they're available to you.
From there, I'm all about vital records. I will use published genealogies from time to time, especially now with the advent of Google Books, but I'm pretty wary of those and tend to view them more as jumping-off points and not gospel. I've been burned too many times by bad information in them, so I always work with local vital records offices or state libraries to make sure I'm on the right track. I'm spoiled professionally because I get to spend a lot of my time working at my state library for my paying job, so during lunch breaks or down time, I can go do my research then. What's nice about my state library -- yours might be different -- is that they also hold or have e-access to a lot of vital records from nearby states, which helps me out tremendously. And if you live a good distance from your state library, your local library most likely has duplicates for your area or can give you e-access. I can't preach the gospel of state libraries enough.
Beyond that, I use a lot of historical newspapers (they usually require subscription access; try your college/alma mater or public library) and LexisNexis (same thing) for records. I also contact local historical societies and churches via e-mail/snail mail to see if they can ever help out, and they're often more than happy to. Using resources and databases that are already free to me, I've yet to find any reason to pay for Ancestry.
What complicates things for me is that my mother is from another country (the Bahamas) and many of my cousins through her came from marriages between Bahamians and people from other countries, including Cuba, Haiti, Chile, China, Germany, Canada (I use my local state university's incredible Canadian government records collection), and so on, so I've had to get familiar with records in many different places. That means sometimes having to work in other languages or turn to crowd-sourced projects like CubaGenWeb, the Bahamas Genealogy Project, CaribSeek, or even RootsWeb. Or Geni, of course! :) But again, verify, verify, verify.
Where I made my mistake was not putting all of my sources in when I first joined Geni. I was using the Flash interface and just kept adding and adding without fully appreciating the individual profile view. So now I'm going back through and adding information into "About Me" fields to try to bulk them up.
Sorry for writing a book, but hey, you asked! :)