I am trying to put up a jpeg of my desktop and it will not allow me to attach it. How come?

You have different possibilities.
You can send it as attachment of your post (File Attachments --> select your file and then "Add This Attachment").  

But for pictures, I recommend you to upload it on an image hosting site (imageshack.us for example).
And then you just copy "Hotlink for forums (1)".  

I'm doing this and it tells me:

THE FOLLOWING ERROR(S) WERE FOUND
The total filespace required to upload all the attached files is greater than your per post or global limit. Please reduce the number of attachments or the size of the attachments.

What is the maximum file size?

That's a good question.  
Which size are your pictures?
Maybe try to convert them in .png, it would reduce the size.  

But the best and easiest way (and the most used way) is the second possibility.  

okay it works now....check it out: ;-)

http://forum.crystalxp.net/index.php?showt...33&#entry112633