1. Can't understand what you wanna know
2. to center image in post you use bbcode like
Code:
[ center]your image link[/center]
and not
<center>, this is html.
3. lol.. how can you link an image to your local PC ??
you have to upload it onto the server to get it that is why you attach it. You can definitely use the features of image hosting site like photobucket, imageshack to host your images and link them easily.