Koopa's Guide to Photobucket
Works every time!
Step 1. Logging In
Put in your Photobucket Account's Username/Email, and Password in this box:

Step 2. Choose the Images
You must click the button that says "Choose Files"

And choose the images you're uploading.
Step 3. Waiting
Wait until the uploading process is complete. It will appear like this:

Step 4. Add Tags and Titles
You may add Tags, a Description for each image, and a Title. This is optional.
When you're done, click the button below:

The image is now in your selected album.
Step 5. IMG Code
Drag your mouse cursor over the image that you want to display, a box pops up. Take the IMG Code:

And paste it onto your post.
You're Done! Congratulations, you now know how to post images on the forums with your Photobucket Account.