Been reading for a while and not quite sure where to jump in? Maybe you would just like to learn more details? Hardware modding/hacking is lots of fun, and can have a very rewarding outcome.
For starters, here is a great article for beginners, covering pretty much all the bases. Also Wikipedia is an excellent source for some beginner knowledge, everything from capacitors, to resistors, to solder, and much much more.
As far as jumping in and getting your hands dirty, there are a number of stores online offering kits ranging from beginner to advanced. Adafruit Industries is a great place to jump in, The Maker Store, and who can forget good old Radio Shack.
Oh, and make sure to check our very own Hacked Gadgets forums
Happy hacking!