Take a walk down the many side streets where you will find shops, cafes, food, candy and of course - like everywhere else in Japan - temples!
Kawagoe is easily accessible and can easily be done for a full day or half-day trip.
As any other place in Japan there are temples to see. I just didn't pay much attention to it, as I was on a somewhat tight schedule.
How to get there? Use your JR Pass
With JR you can come from Shinjuku Station to Omiaya and then on to Kawagoe Station. This trip is covered by your JR Railpass
The easiest way to Kawagoe comes with Tobu, across Ikebukuro Station; a walk of about 30 min. It costs around 470 Yen per day. luck, so for a round of 50s you come home and home quite cheaply. Subsequently, it has come to my attention that there is a discount card for tourists called "Kawagoe Discount Pass" - a discount card, thus providing a return trip between Ikebukuro Station and Kawagoe. Wherever you are in Tokyo, it's easy to get to Ikebukuro, where you can start your journey with the discount card. The card provides a discount for some people and other places in Kawagoe - but is only valid on the date of issue.
With Seibu you can, just like the JR line, come to Kawagoe from Shinjuku station. However, this journey takes about one hour each way.