For learning exposure: Best tips I have..
1. Set your ISO as low as possible. This gives you the least grainy photo
2. Any shutter speed lower than about 100 is more likely to be too slow for you to hold it without a tripod. As you practice, you might be able to get lower. I can shoot at about 40 without a tripod on a good day, but it's easier to bump the ISO one level.
3. Learn w/ your aperture all the way down. most of the time, from your shots, you'll want the blurred background of the lowest number aperture you have.
4. 1 stop down in aperture = 1 step up in shutter speed. This is helpful if you want motion blur (example, moving wheels of a car, etc). You want the shutter open longer without over-exposing.
Any questions, feel free to ask. A lot of us on here know the technical stuff pretty well. In the end, don't be afraid to take the same shot 10 different times with different settings and compare. The data is always in the 'properties' of the photo, or EXIF data and you can see afterwards what the changes did.