Need help figuring out which flashes to get to work together

[babyem]

Please bear with me. I'm a newbie and all I know about flashes is from what I have gathered from reading on here in the last several days. I just purchased a Canon 40D and mainly intend to use it for taking pictures of my children and my friends' children. I plan to set up a small studio in my home. From reading, I have gathered that perhaps an external flash would be the most versitle item to purchase to use both outdoors and in my home studio. And add another flash or two for fill and/or background lights. How they all work together is a little fuzzy to me still so I was hoping someone could help me figure out what I need to get started so that I don't end up with something that totally doesn't work for what I am wanting to do or doesn't work together. I'm also trying to keep the cost down as much as possible so I don't have to have Canon brand flashes. I've been reading pretty good things about the Sigma 530 Super Flash except that the manuals are pretty hard to decipher. Would this be a good 'main' flash? One to use when I'm on the go on my 40D as well as the main light/master in my home studio? If so, I'll need a Hot Shoe PC Sync Adapter for that, right? As well as a PC cord? And for the slaves, can they be models that are just manual control? What would I need to make them work with the master (most cost effectively)? Any suggestions on flashes to be used as slaves?

[Curtis N]

The Sigma EF-530 DG Super is a viable alternative to the Canon EX Speedlites if your means are limited. Keep in mind, you get what you pay for.

Have you seen this thread?
http://photography-on-the.net/forum/showthread.php?t=308108

[Headcase650]

I have had the sigma 500DG super and it was a pretty good flash. I also have a Canon 550EX flash. With prices for the new 530 super being a little over $200 I would look for a good used 550EX for around the same price. Use that as your starting flash, as you advance you will need to decide between ETTL and manual before you buy additional slaves. If you like the automation of ETTL then a used 420EX is the cheapest slave, then the 430EX, another 550EX or a 580EX. If you feel comfortable with manual control you have a ton of more options, manual flash guns from the 70's and 80's are fairly inexpensive used with optical or radio slaves.
Adrian

[babyem]

Thanks so much!

Curtis - I did see that link when I first started reading on here but it was so over my head then that it didn't help much and I forgot it was even there. But, this time, it really helped me a lot. Thanks for directing me there!

I ended up purchasing a used Canon 550EX on Ebay last night so I'll see where I can go from there.

Thanks again for your comments.