Help, coming up with what to charge

So, an old friend of mine who does designing (not web design, but print stuff) referred me to someone who is starting a new business and needs help with his website.

We’ve been talking via email, and he told me he wants to compensate me for consulting him on how to move forward with his site. He said to give him a number, and we can go from there.

Since i’m just starting out, I haven’t even yet come up with a set of rates, but I wasn’t planning on charging any client for the initial consultation… So I’m not sure what to come back with.

Also, for websites, do most designers here have set rates, depending on the size/complexity of the site, or do you charge hourly, or what?

t.i.a!