Let's see -- Thing 1 and Thing 2 were a breeze. I've set up a blog (obviously!), and figured out how to change the look, set up my profile, post, and stuff like that. I've also already set up a del.icio.us account and registered my blog as a new bookmark, so SLA knows I'm doing the "23 Things." It's public knowledge, so I'll have to get through at least the "23 Things-lite" version, or 13 things. So I've covered Thing 3 and Thing 4, and have started on Thing 5. (Why is this sounding like The Addams Family IX?)
The "23 Things" wiki is pretty well set up -- it has useful links, but not too many of them. The stuff is organized well, and is written at the right level for me.
At least I already had worked with a wiki. My chapter (Washington, DC) uses a wiki hosted through SLA to share Board and Committee information. I've been posting financial reports (restricted to Board members) for a few months now. However, we're not doing it at present because the wiki is open now to non-Board people.) I found I still had to think each time about how to go about posting an announcement that new reports are available, but I'm the try-it-and-see-if-it-looks-right sort of person, so trial and error eventually got the job done.
As for blogging, I have to answer for myself some additional questions: Which blogs to follow? Which sites to link to from my blog as being ones important to me that others might find interesting or useful? And so on.
I set up my blog using Blogger (www.blogger.com). It has the basic functionality I desired and allowed me some leeway in choosing my look. And frankly, I chose it because it was first in the list of ones in the 23Things wiki page.
These sorts of decisions are the sort of thing people frequently overthink. Is this the best -- the absolute best -- blog host for me? I have no idea. I don't really care. I gave the decision some time, but as soon as I identified Blogger as adequate and usable, that was all the time I was willing to spend on the decision. Pick one and get on with the next thing.