for computers and electronics brand names wholesalers include, D&H, MaLabs, ingram micro, synnex. ASI, Tech Data, Evertek. these are all big name suppliers. they support U.S. and Canada.
Evertek deals in used and refurb electronics with low minimum order of 1000$. D&H does dropshipping for a small fee, as well as supports xml products. both of those have no register fees. the others require you to pay up a $100-$200 fee to get access and require tax information/enviroment & recycling membership/bank refferences and all that. but prices will be signifcantly cheaper.
I reccommend D&H and Malabs for new retailers.
for toys and games & trading cards(U.S. only), have a look at: Alliance Distribution, Aladdin Distributors, Acd Distribution, GTS Distribution.
if you'd like to verify these. just google for the magic the gathering official site called: Wizards, all these names are listed on there as their official distributors, in a special section of their site. and most of them easy to find by google.
to verify the computer distributors. just go to their site, they are all setup like big corporations. remember you can always research the names on google for your own verification, they are known in many forums, its always reccommended to take in as much about a distributor before choosing to go with them.