WP as CMS – Managing Images

Hey there, hope someone can help me.

I’m customizing WP as a CMS and am literally 95% of the way there but the last hurdle to overcome is the user’s ability to manage the images throughout the WP template (main page, services, etc) through the admin console. I tried using post-thumb to call an image from a specific category/post that the user can change (via the post editor) which worked but seemed to have some resizing issues… the resizing part is important because I can’t trust my users to resize the image before uploading to match the image size in the WP theme. Hope this makes sense and I hope someone’s come across an effective way to do this. Please let me know if you have any input and, better yet, a solution!

Thanks!