I'm so sorry I didn't get back to you! I missed then update email.
I mount the rubber on EZ Mount. It can be found online using that name in the search, so just look for the best price. Don't forget to calculate shipping when comparing prices. Some places offer a great price for the product, but then charge an arm and a leg for shipping.
There are some wonderful video tutorials for putting rubber onto EZ Mount. Google "youtube ez mount" and/or "youtube ez mount hot knife" (without the quotes) to get some results. I recommend getting a hot knife for this job; it'll make it so much easier.
mounting with scissors (also includes tips for using double-stick tape):
http://www.youtube.com/watch?v=6ROM-hOaapM
http://www.youtube.com/watch?v=2mOxt...aynext_from=PL
using a hot knife:
http://www.youtube.com/watch?v=UG7ln...rom=PL&index=5
This video shows the stamper keeping the paper backing, so she has to trim it. I don't use the paper backing to store my stamps , so I don't have to trim the paper. I just put the cling side right on the storage panel.
http://www.youtube.com/watch?v=qgbyk...631422&index=8
This video bugs me a bit because her child is wandering around while she's using the hot knife!
I store my unmounted stamps on thin plastic storage panels meant just for this purpose. They're called Stamp N' Stor Lightweight Storage Panels and they fit into a regular 3-ring binder. They also fit into page protectors, so I slip the panel into a page protector and then into a binder. The cling side of the EZ Mount sticks right to the panel, but if a stamp should come off, it'll at least stay close (in the page protector) until I put it back in place.
There are other cling foam products for mounting rubber stamps. Creative Cling Foam is another brand, and Google will undoubtedly turn up more brands to check out.