Just my 2 cents... And remember, these are only my opinions... (Have to cover my behind because I don't want 30 Private Messages telling me off)
I'm going to reiterate some things, but also add some things too.
1. Don't know about Canon's sorry!
2. Aperture, just because I think it's a lot better than lightroom.
3. Definitely CS3, love it!
4. Monfrotto is okay, have you looked into Induro?
http://www.indurogear.com/ I have one of their larger tripods and a monopod and I can't praise their construction enough and they accept pretty much any tripod head.
5. About lenses, what type of photography are you wanting to start? Portrait is different from Commercial. Sports is different than still life. And all of these have certain lenses that might be better suited for what you want to do.
6. Why get TONS of Cards? All this does is clutter your camera bag and not to mention that with smaller cards you have to change the cards more often and risk losing that money making shot. Get large cards 4GB+ and keep 3 with you. That's 12GB worth of storage.
7. Like Clix Pix says, get external drives. If you shoot RAW, imagine 12MB+ file sizes PER SHOT! And you'd want to shoot RAW, it gives you many more options and (in my opinion) better quality since it isn't compressed like JPEGs.
8. Consider getting that Mac Pro that was mentioned with lots of memory and lots of HD space. I suggest a 23" screen to start with, two 23" or 30" and 23" later on. You can never have enough real estate when it comes to photos.
9. Mentioning screens, don't forget to get a color calibrator for your screen. Why have a great and awesome photo or a photo for a client that's paying cash and not have the photo color corrected?? A lot of people, even "photographers" think that they can get away with not color correcting 100% but trust me, a good majority of people can tell when there is a color off or a color cast on the photo.
10. Also mention was a light meter. Get one. Enough said.
(these are from compwar but I'm just expanding on them)
11. Insurance. I probably have nearly $30,000 dollars worth of equipment between my digital 35mm cameras, medium format, large format, and lighting equipment not to mention the computers and accessories that go with all those. Insurance will save your behind if that lens accidentally falls or if someone breaks into your car and steals everything you have in it.
12. If you're doing portraits, you more than likely need strobe lights. Not everyone wants their photo outside and a person looks better in a portrait indoors if there are strobe lights on them. I prefer Profoto but those are one of the most expensive strobe lights out there. Maybe White Lightning strobe lights? Relatively cheap and decent lighting (IMHO).
13. Printers. That's where you can make a lot of your money! As a Pro Photographer myself, I don't make my money by going and taking the shot. I make it in the prints! Offer packages, 2 8x10, 5 5x7, etc. for $$.$$ then that adds an extra amount to you coming out and taking that photo.
14. Business- Cards, Website, Brochure, Ad in the paper, etc. will get you out there.
(Back to my 2 cents)
15.
Get a portfolio together! I would never get a photograph done without first seeing what the photographer is able to do. I would never have a photograph taken of me or a product if I didn't know if the person could actually take a shot, i.e. composition (not everything should be in the center of the frame), lighting, etc. because that would cost me money and the person time because I would make them go back and redo it without pay.
16. Do you know lighting? Like light styles in portrait photography? Loop, butterfly, 45? Look at places like motophoto, etc. that do portraits. Get dramatic, those sell! Who really wants flat lighting on themselves? With no light direction, the person looks dead and unattractive. And don't forget the catch lights in the eyes (the white dot you see in portraits of people). Those help make the person look alive and inviting and not just dark, black holes into nowhere.
17. Focus! Make sure everything you take is in focus. I'm not saying you don't or can't but some of the photos I've seen taken by professionals, even places like Click and Motophoto sometimes has things out of focus and drives me nuts!
18. Now like clix pix is saying, what have you done before? Where are you at in photography? Do you have aP&S or a DSLR? What experience do you have that can make you stand out above the rest of the pro photographers out there that can get you that job instead of the pro? (And not talking price, even pros will undercut someone else to get the job)
Well there you go, I know it's long but that's my two cents along with more details from what others are saying that I had things to say about also. Good luck!
~Crawn