Go to sites like
http://imageshack.us/ and upload your image, then just follow the instructions there.
Here are a few tutorials if you get lost.
Spoiler for Tutorials:
How do I post Images ?
Spoiler for Answer:
To place an image in a post you must first upload it to a imagehost site like
ImageShack.us or
xs.to
Both of these sites offer this service for FREE 
When uploading images in
ImageShack ...
- Make sure you have these selected...
In some cases the second is better unselected, to warn other members of high load time and the actual size of the image (for example a 2000x2000 resolution image)
- Make sure you copy the Hotlink to forums (1), it's design so that one click will select it all, for easy use Also it contains the VBulletin code necessary for the image to be visible directly in the forum, with the settings above the image, no matter how big it is will show in the forum.
- When uploading large images make sure you copy the Thumbnail for forums (1)
Here's an example of how an image looks if you copy
Hotlink to forums (1)
Remember copy this type of text :
[URL=http://imageshack.us][IMG]http://img212.imageshack.us/img212/5725/randomsigy4iy.gif[/IMG][/URL]
Little tips.- Don't post huge images in the forum (as in don't post them in the forum at there actual size, as long as they fit in a normal window it should be fine) if you have a large one then post the thumbnail.
- Try to avoid clicking Back in your browser. It tends to either cause errors or increase uploading time, well that's how it seemed from my perspective
Just use the frog icon on the left (it's a button )
How do I place an link in an image ?
Spoiler for Answer:
To make it simple, this is basically what the code is supposed to look like:
[url= Adress of the Web Page you wish to link to ] [IMG] Adress of the Image [/IMG] [/url]
For a detailed explanation please read
Catgirls' Post
As for spoilers, you can select the text and use the little animated button. (
)
Or you can read the second post on this page. ^^