just getting started?
I don't think training center sucks, but I don't use it for too much, except I have plotted some of the data in excel to do some performance/equipment testing. It was very useful for that. Otherwise I'm a Motionbased guy (in the interest of full disclosure, they are my sponsor).
Try looking at the "Totals" tab instead of the "Map" tab. There is good info there. Also, it compiles all of your rides in a very oderly way to serve as an effective training diary. GPS knows time and date, so it is effective in a way that cyclocomputers are not. A training log is a very good thing to have.
But really if you want to take things to the next level try out Motionbased. I use the Garmin data to compare and contrast courses that I've never raced to those that I can train on in my back yard. I was able to train specifically for Norba #1 simply by digging up a profile of the course from a winter series race. My intervals and race strategy were then tuned to the profile of that course. It worked well for me.
I could go on and on about Motionbased...
But to answer your question, compared to Motionbased, Training Center sucks, but I think it can still provide valuable info, especially as compiled over time. Also, you can't turn the device on while it is plugged in the USB. And if the Garmin ever crashes on you, hold the "reset" and "power" buttons down for several seconds and then turn the device back on (it has happened to me once, and I went through Garmin CS to find this out).
Have fun with it!