I use Paint shop pro 9, and although I'm just a beginner, it gives some pretty nice results. You have several options depending on what you want, and in this photo, I just colored the white baseboard the same color as the wall, making it all blend better. I actually love the look of the wood floors in this picture. The tool I used to do this is called "cloning". You simply are copying and pasting parts of the picture on another part, so I was copying the wall, and pasting it on the baseboard. You can also do such things as cutting the dogs out of the picture, and pasting them on another background entirely. I use PSP 9 because you can also do animations, but many people say Adobe's Photoshop is good at editing pictures. There are many free photo editing software programs, just do a google. Here's one online site.
Onlinephototool.com: online image and photo editor
Looks like I used a different picture than the one in your avatar, it was in your album.