looking for photo-editing software

One surprise I have found with the iMac is that, while the photo-editing software has some technical features, it lacks a lot of the simple stuff I enjoyed with Microsoft's "paint" - part of the Windows accessories package.

As a teacher, I like to take pictures and then write text on them -maybe a label or caption. I also like to be able to point at or circle a specific part of the picture.

As an enthusiastic amateur, I also like to occasionally stitch three or four photos together to make a panoramic view.

As a blogger, I like to resize photos to very specific sizes.

With iPhoto, I appear to be able to do none of these things. I can blur part of a picture, which is great if I want to remove recognizable features of person's face to preserve anonymity and the crop feature is better that Window's version but if I want to resize a pic the simplest options are "large, medium and small".

I am looking at GIMP, Serif Photoplus and a few other free editing software programs online, but getting GIMP to add a phrase to a picture is overkill. Its not clear to me that Serif Photoplus has an Apple version.

Any suggestions?