How to use these new tools?!?!.....

So, I've signed up for many accounts today!  Twitter, LinkedIn, and Delicious.  And, have been looking through many others from the "go2web20.net" site.

Have no idea how to use Twitter!  I'm now "following" a few people/groups that they said "might interest me" (and they were right!).  But no idea how to find someone specific (i.e. I know Donnita signed up yesterday at the end of our class, but I can't find her/don't know how to find her!!).
Anybody have some tips?

LinkedIn seems a little bit easier to use & I found 2 of my address book contacts on there, so have requested to be their friend (FB lingo....not sure what the LinkedIn lingo is for this!!).  I've also requested to be a part of a few groups that I think would be great to follow for my professional life.  It appears they have to "approve" me.....who knows when that will be!

Delicious.....I think I could really get into this site!  Have bookmarked a few things already, and it shows me how many other people have bookmarked that same site.  I can go to their page & look at their bookmarks that have the same "tags" as the bookmark we share.  For example: I bookmarked a muffin recipe & tagged muffin and recipe.  There were 4 people who had also bookmarked that recipe, so looked at their pages and found some other muffin recipes that interested me.
This could be trouble!  Can't wait to explore this more.....but unfortunately I have a paper due on Wed for my other CACE class that should probably take priority over "playing" with this site!!!

Those are all I've looked at so far.....but am hoping to find a few more this week!