You may want to choose according to the groups in your area. For example, here in the bay area I'm familiar with San Francisco Zen Center, and Spirit Rock which is up in Marin county but has teachers all over the bay area.

It helped me a lot to have a group to sit with weekly. How you feel about the group is a pretty good way to choose.

The individual schools are really pretty similar. Tricycle is a magazine that publishes articles from teachers from the three major schools of Buddhism. When you read it you realize the fundamentals are very much the same in each school.

Once you have studied for a while you will view guilt very differently. Through equanimity you can learn to see things as they really are without judging them. It's hard to explain through this iPhone keyboard, but I can assure you that it's about the best thing you can do to shift your perspective to become more compassionate towards yourself and others.

I do mindfulness meditation, because I like it. "Insight meditation" is another name for a same/similar kind of meditation.

It helps me be in touch with my emotions/body/appetite etc. Even when they're unwell. I would otherwise shy away from acknowledging/considering/contemplating things I don't like. Sometimes this helps me when I feel overcome with guilt (for me I usually feel guilty about minor things that I only feel guilty about because I'm a perfectionist who is appalled by hurting a metaphorical flea. Or, regrets.).

If other people know other kinds of meditation better, I'd love to hear about them too.

I'm rather a beginner. Please ask someone with more experience than me!

Find a style that suits you and a teacher you trust and work with them. Even though meditation is all on you, it helps to have a good teacher to advise you when things get difficult.