Work at your own pace, but try to finish one topic area (each topic contains 2-4 Things) per week.
Record all your logons, usernames, and passwords as you create them, and keep them in a single place.
You may want to open the 23 Things blog in one window and the tool you are working with in another window (or tab) so that you can switch back and forth between them.
Some Web 2.0 tools may work differently on different browsers. If you experience problems, try switching browsers. Make sure your browser is up-to-date. Most sites seem to like Internet Explorer and Firefox.
Be sure to use sites correctly -- some will not like the back button and clicking it may mean lost data.
Check your browser settings -- make sure pop-up windows are enabled, allow cookies, and make other setting changes as necessary.
Most sites like Blogger, Delicious, Google, Flickr, and YouTube will have a Help or FAQ section. Use these to help solve problems you may run into.
Ask a colleague for help. And offer your expertise to them.
Type a description of your problem ("can't change font size in blogger," for example) into a search engine. Odds are good that someone else had the problem and you might find the answer in a forum or group discussion.
When all else fails, move on to something else and try again later.
Many Web 2.0 tools are in beta. Beta sites change a lot and improve or add new stuff all the time. If something looks different, has disappeared, or has a new name, the functionality is probably still there. You just have to explore the site some more. That's life in the Web 2.0 world--challenging, exciting, changing.