I recently had to do something similar and I did not have experience with SQL server either. Although I choose to recode, you can use what you have and convert your calls to tables in an SQL format. Is not a big deal once you understand how to do it. But yes, you will have to revisit the code.
To answer the second part of your question, I didn't find any specific book or publication for how to do work with SQL in FoxPro (maybe I did not look hard enough) but I started working and asking these guys here who, without a doubt, are your best resource.
good luck