Handy Dandy Dave Tip #1 : When you are using things like PowerTeacher where a password is used to access a page or site, it's a good idea to NOT let the browser "remember" the passwords. If you let this happen, anyone could sit down at your computer and just get right into a site (like PowerTeacher) under your username. To keep FireFox from "remembering" passwords, you simply have to go to the "Tools" menu and select "Options". When the window pops up, go to the "Security" tab (at the top) and deselect the "Remember passwords for sites" box.
Yours should look like this:

feel free to check out all the options on all the tabs

Handy Dandy Dave Tip #2 : For those of you new to FireFox, you may notice that under the "File" menu, you can select "New Tab". This opens a new "Tab" on top of the page you already have open. By default, it is blank until you tell it where to go. Tabs are just new windows within the browser that you can load other web sites on without having to surf away from the one you have open or having multiple instances of FireFox open. You can also right click on a link in a web page and select "Open link in new tab". This is very handy for things like having PowerTeacher open while being able to surf to another site.

Handy Dandy Dave Tip #3 : As you get more comfortable with FireFox, check out all the free "Add-ons" you can get to improve your web experience. To see them, go to the "Tools" menu and select "Add-ons". You get this screen:

Although, yours will probably be blank. There are two different things: Extensions and Themes. Extensions add little functionality to FireFox while Themes just make it look different. To get new ones, click on the link in the lower right corner. Once you find an Extension or Theme you like, download/install it and restart FireFox to make it work. You can see some of the ones I have in the picture above. The Answers thing is cool and I have a bunch of others at home including one that gives you a small preview window of a page that will load if you click a link. There are several that allow you to save, bookmark, highlight, etc. specific text from a page.