DIDN'T READ ABOVE:
If you are asking what lens/flash to buy then it doesn't seem you are familiar with photography business.
First steps first (learn how to walk) - LEARN LIGHTING. If you just want to take pics (snapshots) you can do that with P&S. Find an
1d1ot and sell it. If you want to do it RIGHT, learn lighting. My favorite sites that I think are GREAT for beginners are
Strobist and David Ziser's Blog
Digital ProTalk. Ziser did a series of videos for Kelby's Training on lighting both ON-CAMERA and OFF-Camera. Although they are mostly wedding based and classical, if you can bang those out with ease then you can successfully take any portrait of anyone and artistically LIGHT it.
There are MANY other online tutorials out there on light and it isn't revelent which you use, AS LONG AS you learn basic lighting technique. Whatever camera, lens, flash you have now, based on the two above you shouldn't have a problem shooting at iso400 1/125 at f/5.6 (and I hope the values mean something to you - b/c if they don't AGAIN you have a lot to learn).
With that in mind...
Lenses: think simple & less is more. You need wide angle and close ups. Is it BETTER to have 2.8 vs 5.6 YES but if you are using portrait lights,
in terms of lightingother then DoF 2.8 isn't any better then 5.6
Flash: For portraits, use umbrellas, softboxes. On camera flash is usually too direct and even if modified with omnibounce, Fong, foampaper (my personal vavorite) is still flat that is advantage of multiple light units (give your 2D image an 3D look). But if you just need a flash, get Canon's 580EXII. It is more expensive, but in long run you'll probably be happier with it.
Good Luck and welcome to photo.
Post your work for CC (it might be harsh at times, pending who is giving it, BUT it'll give you perspective what someone else is seeing).
Business: photo business is about 75% business if not more and the rest if photography. You can be a great artists but if you can't sell your work... There are hundreds and thousands of
marketing tactics one can utilize and knowing when to use what is IMPORTANT. Craigslist is a 50/50 place - you might get a hit you might not. See if you can get to work with a local photographer, I don't mean sears, and learn from him/her. Many photographers nowadays started out assisting someone and learned various aspects of photography, business that way.