If you want to try you own image editing, I recommend several different options:
1. The absolute easiest (and free) route is the online photo editor PIXLR. You can resize and specify pixel size.
2. Adobe Photoshop Elements is around $150. This will allow you do to very minor editing. You can edit use PSE on your iPad or tablet which is pretty incredible.
3. There is also a free image editing software made to mimic Photoshop called GIMP. I find GIMP a little difficult to navigate because of the complex editing tools provided but I’ve known several clients that quite like GIMP.
4. If you want to use the software Graphic Designers use, the Adobe Creative Suite is the appropriate software bundle. Adobe Illustrator will specifically edit EPS and AI files (which is how most logos are created).
With all of these products there is of course a learning curve as there is when tackling any new software before becoming proficient, but if you are up for the challenge, have fun!