How do I start a Jag that's been parked in garage for two years?

I inherited my father's Jaguar several years ago, and have held on to it as it is very sentimental. I've had a lot of work done to it over the years and loved driving it. However, my Jaguar has been sitting in my garage for about two years and hasn't ran since then. Initially, I let it go for a couple weeks without running it and was never able to start it up again. The battery seemed to hold a charge as I could hear the ignition trying to turnover. I just couldn't get it to start! Getting it fixed has been something I've been putting off as I know its never cheap, but I've decided that it's time to get it running again. I'm not a car guy, so I plan on having a professional make the repairs, but I was wondering if anyone has any suggestions as to if there is any easy fix, or what parts I may need to replace. I hadn't put any fuel stabilizer in the tank, so I'm assuming the gas will have to be drained. I've also read that usually spark plugs, fuel filter, and oil should be changed. Am I missing anything? Any help would be greatly appreciated.