Line-breaks and stanza-breaks in poetry are not dissimilar from punctuation: use them well, and they'll enhance the clarity of your writing, but get them wrong. and: well? you;ll be in all kinds of trouble! then(myfriend).
There is no single right place for breaking lines, or any single rule for doing so, but it's worth remembering that poetry is an oral form at heart. There was poetry before there was ever a page. Lines and stanzas are a guide to how your poem should be recited - where the sense should be emphasized, where the orator should pause in the telling. Read your poem aloud to yourself, and you'll hear clearly where the breaks should go and where they should not.
Even if you decide to attempt a traditional form (ie. a sonnet) the lines must fit the sense, not the sense the lines (which is why a sonnet is a difficult thing to get right). The variety of line length in poetry is a tool. Use it with care and you'll be on your way to creating beautiful things. Use it thoughtlessly and you'll be running with scissors through all your poor shredded efforts.