So I went back to the Internet. After a quick search, I found this video on how to card wool, and then this video on how to both card it and form it into rolags. Neither process looked difficult, so I started browsing for a pair of hand cards, which are a kind of specialized comb for carding wool. They can be expensive--the cheapest ones I've found so far, on this site, are $18.00 USD apiece, and the most common price is about $50 USD for a pair. Somehow, I have a hard time bringing myself to spend $36.00 plus shipping to prepare $2.50 worth of wool. (I'm beginning to think I should have spent the extra money for pre-carded rolags.)
While I was thinking about the carding issue, I took some pieces of fleece that matched in color and texture and seemed to be almost the right shape as a rolag and began stretching and shaping them together. My crudely-improvised rolag is shown on the right.
Then I found this forum thread about the pros and cons of using pet slickers (small wire brushes used to groom certain breeds of dogs and cats) for carding. The gist of the discussion was that proper carders last longer and are more efficient, but that slicker brushes work well enough and are better for a beginner than the so-called "student" carders sold by some companies. (They even have the same shape as wool carding combs!) That was good news to me. I've seen slicker brushes at my local pet supply store for about $8 USD apiece. (I don't own any, despite having a very generously furred cat, because it's more efficient to use a metal comb to groom her. However, I have saved a quantity of her fur combings--maybe I will be able to spin some of them into yarn once I learn the spinning process!)
So now I should probably buy a pair of slickers, card and form a quantity of the wool into rolags, and see what I can learn about spinning.