These are excellent sites which explain each type of meter -- what each one is named and what each sounds like.
Most of the time English will fall naturally into an iambic line -- so then you need to decide how many syllables you want in each line. Make sure it's an even number since each iamb is two syllables.
You could also try a type of poem called a diamante. That name comes from the look of it on a page once you've typed and centered everything.
There are several really good websites here -- http://www.google.com/search?q=diamante+poem&ie=utf-8&oe=utf-8&aq=t&client=firefox-a&rlz=1R1GGGL_en___US321 -- that can help you write one of these.
Post what you come up with if you'd like someone to look it over for you.