just bought a 430EX flash

so i figured the flash was too good to pass up on ebay for 175...so i bought it...now i need to figure out how to use it...honestly i never thought i'd get a flash...but since i got a macro lens have decided that i need it...now i need to know what else i need for macro shots....i'm assuming i need one of those off-shoe cords right?...and a bracket?...and diffuser?

are the off-shoe cords off ebay o.k.?

Avoid the off-brand off-shoe cords unless it's from a reputable retailer with a good return policy. Lots of problems have been reported with non-Canon TTL cords. Promaster makes a good one, but it will probably cost you nearly as much as genuine Canon.

For the rest of your questions, the answers lie in how you want to light your shots. Once you understand light, you can make intelligent decisions on equipment.

Start with this thread:
https://photography-on-the.net/forum/showthre​ad.php?t=142566

And learn about light here:
http://strobist.com (go to the lighting 101 stuff)