My suggestion is that you spend some time familiarizing yourself with life online. Without a doubt you will quickly be swamped with offers of the next best thing and information overload, believe me this can be rather intimidation.
The other factor to consider when exploring how to start a web business is, how big is your budget? Yes how much money are you prepared to invest? Surely you will not try to buy a Starbucks with no money down. Similarly you'll have to invest some money in an online business.
Then there is the time and effort it is going to take. Any business for that matter can be absolutely tyrannical in this area. Many careers today require most of our time during the day, if you are not in meetings you are commuting, you know the drill.
So what are your reasons for wanting to know how to start web business? For me it was the power to decide my schedule and the freedom it gave me to work from where I wish don't be fooled the money is not too bad either and the growth prospects are phenomenal.
When I finally answer my search for how to start a web business, the conclusion I came too was rather surprising and the simplicity shocked me all the way down to my socks. The other amazing factor was the very low entry requirements, miniscule in comparison to other business models. The same goes for the time it takes the average newbie to become successful to the extend where he/she can fire the boss.
Perhaps you've guess what I'm talking about already but if you have not, it is affiliate marketing, hands down the most powerful online business model for the guy on the street. Using effective systems like taught at "The Wealthy Affiliate University" you can build yourself a very lucrative web business within a short period of time.