Okay, I looked at my crazy taxes. Per my tax people, you want to fill out a Schedule E, the Supplemental Income and Loss form (note: I made less than $10,000 in supplemental income -- other forms may apparently apply if you make more).

The bits you fill out are line 4 ("royalties received" or how much money you made per the W2), line 8 ("commissions", if you have an agent), line 15 ("supplies", like pencils, paper, how much internet access you think you might have spent on whatever you were writing, etc.), line 16 ("taxes" -- I have no clue from where these are derived, but it needs filling out), and lines 19, 21, and 22 (to total the whole thing up).

Interesting things from the instruction sheet that apply here:

Report on line 4 royalties from oil, gas, or mineral properties (not including operating interests); copyrights; and patents. Use a separate column (A, B, or C) for each royalty property. Be sure to enter the total of all your royalties in the “Totals” column even if you have only one source of royalties.

If you received $10 or more in royalties during 2008, the payer should send you a Form 1099-MISC or similar statement by February 2, 2009, showing the amount you received.

If you are in business as a self-employed writer, inventor, artist, etc., report your royalty income and expenses on Schedule C or C-EZ. [Note from Cass: So far as I know, though, you're not currently self-employed as a writer.]

I hope this helps -- or at least, makes the confusion go a new and fascinating direction.