Don't spend another penny until you get, read, and digest, this book. http://www.amazon.com/gp/product/0321832752/ref=as_li_ss_il?ie=UTF8&tag=pasoroblphot-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=0321832752
He has another book too, but this one is more appropriate for you. If his rumoured 600 EX RT book comes out I'd recommend that but it hasn't appeared yet and he now has a full time educators job.
Thanks privatebydesign for the link. I just purchased the material and will try to go through this weekend.
I'm interested getting some lighting for home studio. Not sure if I should get some 600ex rt or just regular studio set. I like the ideal of having speedlite so I can take with me if need it. Any suggestions? Thanks
For a home studio I think the Speedlite route is the way to go. They are nowhere near as powerful, but for most people they are way more practical.
Stands: Manfrotto 420, a boom stand should be everyone's first stand, then I really like the stacking Manfrottos at whatever size you like, I have the BAC 1052's.
Umbrella brackets: There are many but the Manfrotto 026 (?) is the industry standard. I'd go for metal ones over the poly and plastic ones.
Modifiers: This is where it gets involved, but I'd suggest a Westcott Apollo 26" softbox, I prefer them to the Lastolite style. A convertible umbrella. A 5-1 reflector around 36" and I really like the collapsible style 78" kits, they give you huge scrims as well as black and white backgrounds.
This gives you enough to play with and to see what kind of light you prefer and the direction you'd like to go in, without committing too much money to something you won't use in the future.
Get a couple of gel sample books from B&H too, they cost $2.50 and are so much fun, they also teach you a huge amount about where your light is going.