I think that you may find it challenging to make money from this, although there is quite probably a market. One of the questions would have to be how are you going to build a customerbase? What it is that will get the potential cyclist who just changed channels at 2 in the morning, saw the tour de frankfurt and realised they were fat so wants to get a bike, to come to you.
I think you'll need to have a fairly clear idea as to how you are going to actually make money from it and build up a small business plan stating this, showing the costs, etc.
After then you'll be sweet. Put in the hard yards, make the most of our wonderful tax system that benefits those who lose money and I am sure you'll be able to do it. Just be prepared that most new businesses don't make money for the first couple of years.
Go for it!

RideStrong have set up their 'Getting Started, Getting Better' section here... http://www.ridestrong.org.nz/RS/blogs/new_to_cycling/archive/2009/03/26/getting-started-guide.aspx

Agree with all the above:

- if you want to do it, give it a crack and see what develops. You'll soon find out how to adapt the model to make it work better. Spend MOST of your effort getting feedback and listening really carefully to it

- remember that what people want and what people will pay for are two different things. Many people will believe they can get their advice on all the stuff you are offering just by surfing the net for a few days (and in a lot of ways they'd probably prefer to do that)...

- what is your (percieved) competitive advantage? Are you well-known to the average beginner cyclist? Many people would pay to get bike advice from Sarah Ulmer for example, but not necessarily from some random person they've never heard of. Even though the"random person" might actually be better qualified to offer advice to a beginner... Do you have an impressive-sounding CV you can use as a marketing tool?

Try it out first, for free maybe, on some friends or acquaintances.