The College Board is much less forthcoming with exam descriptions than DANTES, providing free online information that is little more than a "tease," then offering more detailed information for a "nominal" fee (currently $10 / exam). A more cost-effective solution is to get the CLEP Official Study Guide, or simply to rely on the "unofficial" descriptions in one or more of the better test-prepartation books available from a variety of publishers.
The Princeton Review's Cracking the CLEP is very popular, even though the current (4th) edition devotes considerable space to the "general" exams (which have been discontinued). That information is still useful, and all the subject exams are also covered. Obviously one book will not prepare you for 35 exams, this is just an outline of what subject matter you will need to study and a few example questions. Test-prep books covering a single subject may be adequate preparation, depending upon your current level of knowledge in a particular subject.
You should also be aware of the Advanced Placement (AP) program. Depending upon the admitting institution's policies, it is used to grant class placement and/or college credits. Comparing the credit recommendations of various schools, it becomes clear that the AP and CLEP exams cover the same material. Therefore the AP study materials are perfectly adaptable to the CLEP exams.
Amazon does not presently subdivide their CLEP section, nor is their search function particularly helpful. Pending further expansion, we are featuring one representaive review text per exam at this time.