You have several options to choose from depending on which tools you have and how handy you are.
The most commonly available, recommended adhesive is 3M Photo Mount. It is a spray and sells for about $13.00 for a large can. One can should do quite a few prints. Other permanent adhesive that you might consider are 3M General Purpose 45, it is advertised as "Photo Safe" and cost about $5 at Home Depot. Also 3M Super 77 is slightly less expensive than Photo Mount, and the procedure for using it is the same. It is not advertised to be archival. I know several people who are using this and have been happy with it.