I was diagnosed with cancer at 25, and underwent multiple rounds of chemotherapy and was out of work for some months. I was working at a small software company ~25 people. Outside of the advice that has already been given, I was very glad everyone around me so understanding and willing to help. When I say willing to help, I mean people can really rally together. I took paid my vacation and short term disability, and my employer continued to cover my insurance and hold a position open for me without ever asking when I was coming back. They never gave up on me, and I wouldn't expect any less of your employer. Once you have a diagnosis, the doctors and nurses can really help point you in some good directions if you need any financial or insurance assistance. Also, don't be afraid to ask questions. Write down questions and answers, write down prescriptions, doctors orders, ect. Don't be afraid to lean on those that care about you and ask if you need help (not financially, but with tasks, errands, or just to hang out).