There are many reputable shops out there. If you're ever curious, look up the shop on www.resellerratings.com
. You'll quickly find out if they're good or bad.
Another quick way is look on their website for a mailing address or retail locations. If it's hard to find... stay away. If it's located in Brooklyn, NY... stay away (that is a stereotype, but it holds true for 90% of bad online vendors)... and if they have a phone number in 718, stay away...
Good: www.adorama.com www.samys.com www.bhphotovideo.com www.glazerscamera.com www.calumet.com www.ritzcamera.com
BAD (STAY FAR AWAY): www.digitalliquidators.com www.broadwayphoto.com www.royalcamera.com www.amphotoworld.com www.ubdigital.com
If you want to see what those bad camera shops' "stores" look like, take a look here: http://www.panix.com/~donwiss/pictures/BrooklynStores/
If, after you place an order, you get an e-mail telling you to "call to confirm your order"... chances are it's shady. Usually, they want you to call so they can up-sell you on accessories, and if you don't buy more things, they'll tell you that your item is back-ordered, even if it says "in-stock" on their website.
There's a lot more I could write about buying online..... but the best advice I can give you is that if something feels at all shady or sketchy, don't commit to it.
I worked in a camera shop for quite awhile, and I've bought a lot of camera equipment from various places over the last 5 years...I've seen how a lot of these things go down.
EDIT: fixed incorrect link
(Message edited by isler on September 01, 2005)