There is a book for Front Range spring descents. It covers some stuff on Berthoud pass. Otherwise I don't think there is a guide for the place, and it should
be that way. No worries, the pass is easy to figure out. The nice thing about it is you can "discover" what it has to offer as you go on. Hook up with some people at the top of the pass and do a tour with them. I do it all the time. I generally look for the people who are coming avy prepared as they tend to have a better chance of having some bc knowledge than all the bootpacking snowboarders and skiers.
Now a days I am generally the one giving the tours, still there is a ton of terrain out there. I am looking forward to doing more exploring this year.