As you know from reading this website I like to make as much as I can from scartch. So naturally I would want to make my own soda pop. So I searched out for a book that could help me with this. "Homemade Root Beer, Soda & Pop" by Stephen Cresswell was the only book I could find on the market that was solely devoted to this subject. So thank goodness this is a good one. It is packed full of recipes from everything from root beer to lemon-lime soda to ginger ale. Many of the recipes contain ingredients that can be found at any grocery store. Some of the stuff for making root beer will be harder to come by, but if you can find it it's well worth the effort (just for the fun of it!).
The author of this book is really into history and he gives a lot of history on the origins of root beer and other drinks. He also likes to include really old recipes. Also to be found within the binding of this book are sections on equipment and how to come up with your own flavors. If any of this sounds interesting to you, even if just for the history, I would recommend buying or borrowing from your local library this book.