best online broker is one that gives you direct access to the market(s) you want to trade. commissions wise should be from .003 to .006 per share. that means 30 cents to 60 cents per 100 shares. firms like td waterhouse that charges some $9 to $14 per trade are ripping you off. plus they are not direct access. this means they have traders will be working your order legally ripping you off by you paying more per transaction aka higher slippage.
a good firm would be interactive brokers or light speed. i know ib caters to canadian clients but don't know about light speed though.
