Things newbies need to understand:
-its actually WORK!! yep, you'll be at the pc 8-12 hours a day, 6-7 days a week with little-to-no paycheck for a month or so till you start "building your empire"
-you have to LEARN how to do new shit. If you have this "ahh i dont need to learn that" mentality, get out before you even start.
-network with other webmasters. (keep a clean rep too.)
-takes money to make money. be prepared to shell out cash for hosting, domains, a design here and there, and other useful tools to help you along the way.
-read & learn something new in this biz everyday. its constantly changing, so keep up or get out.
if you cant handle all of this PLUS more, dont even bother starting.
If you think you can, well then, welcome to the biz.