Jmkm,
Selling Poetry Is NOT a reasonable way of making money. FEW if ANY markets pay in anything but copies, and except for "The New Yorker" and the "Atlantic Monthly", only a handful pay $50 or more and they are EXTREMELY hard to break into.
If you want to try though, you don't have to rely on the "Writer's Digest Poetry Yearbooks" There are many listing of POETRY MARKETS (including Paying, Non-Paying Markets and Contests) that are available on-line including:
http://www.writerswrite.com/poetry/markets.htm
http://www.bryantmcgill.com/Friends_and_Artists/Poetry_Contests/
http://www.drowningman.net/poetrylinks.htm
http://www.dmoz.org/Arts/Writers_Resources/Contests/Poetry/
http://www.poetrymachine.com/homepage.htm
Other rsesources, such as TRAINING TOOLS, (which also contain further links to Contests and Markets), can be found at:
http://www.publishing-explained.com/index.html
http://www.textetc.com/
Legitimate Poetry Contests do have reasonably large awards ($2000 -$5000) but most are for "Collections of Poetry" and require $20 - $30 for entry or reader's fees and only award one winner. Smaller Contests that reward single Poems usually require small fees of $5 - $10 per poem entered and reward only a few Poems at most, (and mostly in Publication rather than cash).
Moreover, you should try to read any publication you submit to (which can sometimes be done on line if they can't be found in a Library or Bookstore) in order to see what kind of Poetry they accept and be prepared for endless "Rejection Slips" in any case as even the smallest markets are highly competitive.
Poetry.com The National and International Library of Poetry, and any contest that is indescriminate in the winners they select and requires payment for inclusion in their "Anthologies" are SCAMS and should be avoided at all costs. (Check the Poetry.com and Poetry.con threads on this site)
I've been trying to get my Poems published for 47+ years and have managed to place only 15 Poems, and only 2 of those paid, (one for $1 and one for $15)
In any case, I wish you the best of luck at Publishing but suggest you look elsewhere for paying for that car.
Write On,
Jim Hoye, (JRH)