It's important to know your machine.
I would practice at some schools or parks to get more familiar, and to maybe even find a few bucks.
From there, research out good areas by trying to find the area's history.
Since you said you got a cheap Radio Shack detector, I might suggest picking up a slightly better one.
You can find something like a White's Prism for around $150-200 on E bay, or even post something on this site stating that you are looking for a detector.
You will probably like it better, find more things, and become less frustrated and enjoy the hobby even better.
Remember, that you will be finding $$$ so if you get out and hunt in some good areas, before you know it you'll find more than the $150-200 that you initially spent on it!
My first detector was a Whites that I paid $170 for, and in one school alone I found over $400 in coins in a summer.
Good Luck!