Every bank has an investment institution that has a retail section for trading stocks, such as rbc,hsbc, td etc. Depanding how you want to trade, how much you want to invest, how frequent you want to trade, they have cash account and margin account. the latter allow you to trade with a loan from bank.
there are also some discount brokers such as E trade, Amtrade,and a bounch of others you can open an account to trade. They are somewhat cheaper than bank in commission.
In most cases you can trade by phone, or trade online.
if you trade stocks in RRSP, use etrade.ca
if you trade mutual funds, then use investorline by bmo
if you trade us only stocks out of RRSP, then use ameritrade.ca