Multiple the_content or something tike that

if you can’t do what you want directly through the post editor, custom fields are often very useful. I use them to add all sorts of stuff to my posts

http://codex.wordpress.org/Custom_Fields

well… have you used WPs in-built gallery feature?

You can do pretty good with that…. you can place it where you want in your content with a short code. Getting it to look how you actually want is done in your css. Your theme may already be set up to make it look good….. if not, you can peek at the twentyten theme, or another theme

http://codex.wordpress.org/Gallery_Shortcode

This is how mine looks…
http://www.rvoodoo.com/life-voodoo-style/lights-before-christmas-gallery-test-post/

thats just how my theme lays out the gallery….