"Once you get the steps down" being the key words?
I'm a huge believer in DIY, but I'm also an ex RV tech? I've seen and repaired the results of that first attempt at winterizing way too many times. I would suggest you have a mobile repairman come out and do it for you/show you how while you take pics and notes? This experience awesome for gaining first hand experience regarding YOUR coach. This lets you get to work in the future (like when returning from a spring break into freezing weather?), without having to sift through all sorts of generic info.
Unless you are very mechanically inclined, it's very possible (and very common!) to miss something important, and that lesson can be an expensive one!
If you're determined to try it yourself, some of the more common problem areas I remember repairing frequently are low point drains located in out of the way places, water heaters (!!), toilet valves (!!!!), water filters and appliances like ice makers and washing machines, city water hook ups, and water pumps?
1997 37' HR Endeavor, 275hp Cat, Freightliner
03 CR-V Blue Ox, Ready Brake