All of the above advise is great! I'll add my own 2 cents.
There is a great resource for doctors called UpToDate, it is a service that compiles and presents the most up to date research on any medical copy. Some health centers may be able to give you access through their libraries. It is especially helpful if you have a less common kind of cancer that doesn't have standard protocols. The research is academic but presented for doctors to be able to use it.
If you have a university nearby, or possibly even a community college, you can access many journals online at their library, take a thumb drive with you, you can down load them and read them on PDF later.
Use the information from the NCI, NCCN, PubMed, etc. for a base of knowledge. Find out what cancer center is leading the field in you particular diagnosis. Get educated and get second and third opinions. Consider the relative benefits of different treatments against the longterm side effects and quality of life. Keep a notebook of the questions you want to ask and the conversations and answers that doctors give you.