Embarrassing confession time: I took way, way too long to get comfortable with graphics tablets. The first time I used one was at my first paid Photoshop-intensive job. I learned a lot at that job, but the work was, shall we say, not exactly high-end. A tablet wasn't seen as a necessity for the work I was doing, but I mentioned that I wanted to learn how to use one, and my boss kindly dug through his drawers and found an old tablet I could use. It was a tiny, tethered thing, several generations past its prime. Although I tried to use it as much as possible, I found it incredibly awkward, and allowed my delusional self to imagine that my mad mouse skillz made the tablet superfluous. No tablet was provided at my next big gig. I didn't mind, and moved on.
Then, some time later, a professional retoucher very generously took me under her wing. She let me observe her technique with her tablet and suddenly I felt like a complete idiot for not being more serious about mastering the tablet. My eyes opened, I started working with a tablet again, and much to my surprise and delight, it resulted in the single greatest leap in my skills since I got into digital post-production. As crucial as it was to have someone experienced teach me proper technique, it was every bit as important to use a tablet that is a) reasonably sensitive (you should be able to navigate menus without awkwardness), and b) a decent size. If you've struggled to get comfortable with graphic tablets, the problem may not be you; it might be the tablet. Once you've worked with a good graphics tablet, you will never go back to your sad little mouse.
While I'm being a shameless shill for the graphics tablet industry, I might as well just go ahead and say it: the Wacom Intuos4 is the business, and you should sell your mother to get one, if necessary.
Incidentally, if you look up 'graphics tablet' on Wikipedia, you'll find this little tidbit: "In 1981, musician Todd Rundgren created the first color graphics tablet software for personal computers, which was licensed to Apple as the Utopia Graphics Tablet System." Now you know. Also, Giorgio Moroder helped design a supercar, but that's a story for another day.