shoe mount flash help

[boonbear]

I want to get a decent flash for my canon rebel xsi. The problem is I don't know anything about the flashes or how to pick one out.
I tried to do a search for something to explain external flashes, but I didn't find anything.
I now that guide numbers are used to describe the flashes, but I don't know what they are. And I read a few posts where the flash was slower than the camera, and essentially useless. I definitely don't want to run in to that.
If someone could give me a link or explain the flashes to me, I would appreciate it.
Thanks

 

[KmH]

Here's some info on GN, guide number:

Guide number - Wikipedia, the free encyclopedia

All flashes need time to recharge.

Most DSLRs can take at least 2 or 3 shots per second. The best hot shoe mount speedlights need at least a couple of seconds to recharge to full power.

Some of the better speedlights and cameras do have a feature that lets them fire fater, but they can only do that when the flash is operating at less than full power. Nikon calls it FP-Sync, Canon calls it HSS or high speed sync.

Here are some camera flash tutorials: http://www.cambridgeincolour.com/tutorials/camera-flash.htm and you might visit www.strobist.com.

 

[Big Mike]

I'll just cut to the chase....get a Canon 430EX.