Sodapop - A quick look at the Walgreen's photo book tool and it appears that you need to create your book using their online tools. One option is to create a collection of images you want to put in your book and export them to your hard drive and then upload them to Walgreen's. You can then use their online tool to create your book.
Another option is to create a custom print template using the page dimensions you will use for your photo book. You can then drop the images you want into your custom print layout and print to JPEG. This can be used as a full page image in your book, even though you will have multiple images on the page. I've used this a few times when creating custom book pages for Blurb books. Photoshop has all the tools you need, but if you don't have Photoshop, the Lightroom print module will get the job done.