http://www.nccn.org/professionals/physician_gls/PDF/nhl.pdf
its a pdf file, page 31 is the spleenic diagnosis and treatment page, start.
Click on the blue link to continue on page 31.
I can strongly suggest to print a few pages out, and then start googling all the words you don't know so you can become familiar with what tests are standard for that type of cancer. For breast cancer and other cancers, some docs look at certain cancer markers in your blood, or certain white.red blood cell counts, ask which markers need to be watched and then keep track of those markers. Its over whelming trying to find information. So, print out some and then start marking up the words you don't know and write the meanings on the page.
After you read the stuff for a while you can kind of figure out what things mean. Some people are able to read the journals, and stufy information, its very technical jargan. But for my mom, after you read, re-read, you start to learn the terms, so i would encourage you to do so.
Another thing, I encourage you or some other family member to go to all appointments, and take notes. Write things down. You won't remember what they said, or will forget and the words are huge strange, and not common, and they blend together if you read alot on line.
Make a list of questions for your doctor, don't be afraid to ask those questions. I always had mom/dad ask there question, and then i would ask mine. At first i felt akward, but my parents were a little afraid to ask question, and i felt i was kind of stepping on toes, but asking questions. But, i know they appreciated. If your doc doesn't like answering questions, well, i recommend finding one that wants to answer your questions, etc.
I will tell you when we went to a major cancer center, they gave us a list of treatment options for my mom. Esentially, she recommend one set of possible options. It was a multi-chemo (several chemos/drugs) at once. With several options in the mix, which we essentially picked which drugs she would take. Yes, that is strange to think about, but its a lucky guess to figure out which of the drugs may work, or not work, as everyone is an individual, i mean depending on the type and everything, certain things are ruled out. Just want to warn you about that, the major cancer center kind of always presented things like that. You kind of look at the site affects, and possible positive outcomes, etc, and hope for the best.
I also recommend you find some type of relaxation type thing for yourself during this stressful time. It can be overwelming. So, take time out for yourself to relax and destress, same with your mom.