How do I change my profile picture and how do I make my images the right size it wouldn't let me put any pics in my thread ?
For your profile or "Avatar" pic to the left, that is in your user control panel. Look at the left margin for User CP. Then find the "Edit Avatar" link.
For Pics in Posts, yes there are size limits. You would have to modify those elsewhere. Most computers have a picture edit function. Some handhelds do not.
If you still have questions, drop me a pm.
Last, please read the guidelines that are applicable to pictures.