You shouldn't really need to edit the jReviews template file. There's 2 options:
1) I think jReviews already has some Facebook features for Like buttons included. You should be able to enable this, but it may cause some problems... if so, let us know.
2) You can use the JFBCLike module and place it on your review pages in a module position that would look good for you.
3) If you really want to modify the template file (to give you the most flexibility of placement), when you find the location the Like button should go, simply type {JFBCLike}. JFBConnect will take care of the rest. Make sure this is in an HTML area of the code though, not in a PHP block. I hope that make sense.. if not, I can explain more.
Finally, in either case above, you can use the OpenGraph features in JFBConnect to describe the page's contents to Facebook. For instance, {JFBCGraph image=http://linktoreviewimage.jpg} will set the image that Facebook will use when someone Likes the page. You can either set a default image for the whole site in the JFBConnect Social configuration area, or individually on each page using the tag.
We have a lot of flexibility, but understand, it can be confusing, so if you have any other questions, just let us know!