Here is how to resize your pics. Once you have the right size, then uploading is easy, just Like Ranger explained.
1. open your picture up
2. right click, then click edit
3. will open in the paint program
4. click on image (the top toolbar)
5. click on stretch/skew
6. you will see 2 sections, one for stretch and one for skew
7. under the stretch, change the percentages to 50% each and click ok,
8. Repeat steps 4-7 again.
9. then click file, save as, type in a name, make sure it says jpeg and voila! smaller pics