Poems & Songs New Book

Releasing a book of poems is fine, but if you intend to interest people in setting them to music on spec, you may need to provide some kind of licensing process to allow them to do so. In the US and most of the world, setting a poem to music is creating a derivative work of your copyrighted poem. Even making a single recording of a song with your lyrics without clear permission to do so is technically an infringement of your copyright. Although you could just include language in the preface or introduction that essentially says you are welcome to use these poems to make your own songs, it would be hard to do so in such a way that all the ownership issues would be resolved.
 
If someone creates a song that makes money, do they share revenue with you as co-author? If two publishers want to acquire all rights to two different songs with the same lyrics, can you assure them both that they each will have exclusive rights? The possibility that some composer will be unable to do anything with his melody that is the perfect match to your poem may be a disincentive to theoretical collaborators.
 
If you want to give the poems to the world for free, then something like a Creative Commons license might work, but if you wanted to do that I expect you would not be putting a price tag on your eBook.