Delicious is a place to save your Bookmarks or Favourites so that you can access them on any computer at any time, it is also a great resource by networking with other teachers and sharing their bookmarks as well.
Slideshare is a great storage place for your documents and slideshows. It allows you to embed your docs/slideshows in wikis or blogs. It is also a great resource place to look at and download other teachers docs/slideshows.
To set up a Google account you need to get Gmail, this is important because it will allow you access to Google Docs a very useful collaborative tool and a place to save documents that can be accessed on any computer. It allows you to create blogs in Blogger, and access to a lot more Google tools.

Set up a question for your students/teachers to answer with sticky notes on a Wallwisher. They can add maps, youtube movies, text only or photos to the stickies.
A Jing account allows you to take screen captures and then annotate them with words, arrows and boxes, perfect for making instructions.
Register a Wikispaces account so that you can join any of the wikis I have made or that other educators have made. Do this so that you can comment and collaborate on them. You will also one day might want to make your own professional or class wiki.
Create an online storage system with Dropbox for you and your students files. This could be a place where students store their work for marking, or where you could store files for them to access.
I recommend that you have at least 3 browsersMac (Safari, Firefox, Chrome)
Win (Explorer, Firefox, Chrome)

Create an avatar that you can use to represent yourself online and also to use as a digital marking sticker for marking student's work
Join Twitter and find great websites, follow your peers and experts, share information.