There are many ideas in the Back to School with Web 2.0 posts (http://tinyurl.com/yejzzq is part 3 with links back to parts 1 and 2) and a few in this report (http://tinyurl.com/2t67v6 p5-7, disclaimer, I was a co-author).

For Flickr fans, this is my favorite Flickr educational image about Flickr (http://tinyurl.com/33qeob ).

My own favorite tool is del.icio.us
My top hints in using it successfully are:
i) Install a browswer extension.
ii) use the notes and tag fields extensively for successful later retrieval by searching in your bookmarks using del.icio.us
iii)Select text in the page you are to bookmarking before bookmarking to put that text in the notes field automatically.
iv) learn what the + sign in delicious pages does
v) Try not to become obsessed by bookmarking.
More hints http://tinyurl.com/2ohc8z
+/- 250 Web 2.0 links in flickr http://del.icio.us/mvh/web2.0