Look up the side effects details online - drugs.com and crazymeds.us are good spots to check.

You have to decide for yourself whether it's an acceptable risk. Most people don't have problems with the meds or else they wouldn't be so popular, especially among people who aren't prescribed them.

As far as "good" goes, that depends on whether it helps your symptoms.

In my opinion, extended release meds are better and less tempting for abuse. Ritalin is instant, but I think Concerta is the extended release version for the same active ingredient (might be wrong on that, though.) Adderall is usually preferred for adults, and for that one, the XR is a ton better for me than the instant release.