It seems that a lot of people don't understand how to put pictures in their avatars or profiles. This isn't going to explain how to create an image using photoshop or anything, my guide assumes you already have a picture you want to use.
IF THE PICTURE IS FOUND ONLINE:
1) Copy the picture's URL by right-clicking and (for internet explorer users) going to "properties" and copying the given address, or (for firefox users) right-clicking and choosing "Copy Image Location."
Internet Explorer-
Firefox-
2) For an avatar -
-open your n00bfest profile (go to the forum index and it's at the top of the page, next to "n00bfest").
-scroll down to the bottom, a section called "Avatar Control Panel". Paste the URL of your desired picture into the blank, and click "Submit".
3) For a signature -
-again, open your n00bfest profile, but scroll down near the middle, to a section called "Profile Information". The bottom field is where you input your signature.
-To include a picture, copy its URL in between brackets. (This is the same thing you do if you want to include a picture in a post.) Click "Submit".
IF THE PICTURE IS NOT ONLINE:
If the picture you would like to use is on your PC, and not online, you have to find someone to host it online (in other words, put it on their site). Sometimes you can ask a n00bfest elder to host it on n00bfest, but it's much more practical for everyone if you instead sign up for either an imageshack (www.imageshack.us) or photobucket (www.photobucket.com) account. These allow you to upload multiple pictures from your computer onto an account, and then they give you a URL to use for each one. For example, all the pictures in this guide I hosted on a photobucket account.