Google has some fantastic potential for you to find whatever you are after on the internet.
To search for a book / program / file perhaps try the following.
Go to Google's search page and use the following criteria in the search dialog
intitle:index.of? file extension Name of item
e.g. intitle:index.of? chm syngress
This will hopefully give you a listing of all websites that google has cached that contain references to files in CHM format that are published by SYNGRESS.
I use in Google
+("index of") +("/ebooks"|"/book") +(chm|pdf|zip|rar) +syngress
allinurl: +(rar|chm|zip|pdf|tgz) Syngress