Where to look for the API documentation?

Just recently i read Peter Seibel's fantastic book "Practical Common Lisp". Now i want to do something real with Lisp. I wonder, where i can find the documentation of the functions available in Lisp-In-A-Box? Especially i'm looking for the socket functions of Lisp-In-A-Box, which i could neither find in the hyperspec nor in the ACL Docs

Probably this has been discussed thousand times before, but i searched the internet and the usenet and couldn't find any pointers. So any help is appreciated a lot,

Tia,
Ralf.
.