Whoa Nelly! As I get a bit more serious about writing poetry and learning about prosody, scansion, metre, etc, as opposed to just writing what I think sounds good, I'm realising how much we didn't learn in school! I remember 'iambic pentametre' from my Shakespeare days, but I didn't ever really grasp what it meant.
There are some great resources on the web for helping numpties like me come to grips with the technicalities of poetry:
Wikipedia entries on metre, prosody and scansion
Interactive quiz on metre
Discovering the iamb and the trochee
(I'd be delighted if anyone would provide further relevant links)
You need to know them in order to use them to your advantage, to break with tradition, or to use traditional constructs to create something purposely formal or constrained.
The below poem is in 'iambic trimetre', meaning there are three 'feet', each of which comprises two syllables, the first unstressed, followed by a stressed syllable, except the fourth line, which has an omitted unstressed syllable. I wrote it after a shocking night last night, where I was febrile and delirious in turns. Noice!
Through my delirium
I can't get past 'I can't';
The words they will not budge.
Tears escape my eyes,
A sleep of toss and turns.