This is a fairly quick and dirty go at it:
link to psd file
What I did:
1. Created a new photoshop the size you wanted (7x10)
2. opened the 10 jpgs in photoshop
3. resized the original images, using "Image| Image Size" starting with number 1
4. selected the entire contents of the image and copied
5. pasted that into the blank photoshop
6. dragged the image into place.
I think this is something you might want to do yourself
- you may want to crop the images (for example to make the outside ones a standard shape)
- you may want to overlap the images (which I mostly avoided).
Hope that helps.
edit - this is a shrinked | medium quality jpg of the linked psd file:
