How do learn to write a poem?

I don't honestly know if there's a specific book that will tell you exactly how to write a poem to a girl. There are probably a lot of books that help write poetry, but I think what you're looking for is a manual of sorts.

You don't need a book for what you want to do - just do it yourself. Read some of Shakespeare's sonnets for a place to start. Any poetry class I've taken is based on reading and understanding published poetry before tackling any writing by the students. There are a lot of forms to poetry, and the one people seem to use the most is free-form or free-verse. It's a fairly open format.

Write about how you feel. Pretend like you're writing a letter to this girl, telling her all the important things you want to say. Then read it a few times and find a few keys sentences or phrases that are your main points. Then, start thinking about the lines in the frame of a poem.

Check out poetry.org for heaps of free poetry.

You can google "Poetry" and come up with tons of stuff

and/or, read some of the poems by the posters here. There

are quite a few good poets.

http://www.shadowpoetry.com/resources/wip/types.ht...

this site gives you types of poetry with definition on how to write that form and examples of it.