I get numerous emails everyday asking which online stock broker is best for penny stocks.  There are many but the following are ones I recommend for their price and ease of use.

Ameritrade

Scottrade

Etrade

Think or Swim

Zecco

Ameritrade is by far the easiest and allows trading in most stocks.  Their online trading system is also easy for novice traders but can integrate into more complicated systems.

If you’re going to start investing or trading online then you will need an
online broker.  This is basically like a bank account that allows you to
place trades online.  Certain online brokers have special services that
cater to a certain type of investor but for the most part, I will list the most
common brokers that most people use.

Ameritrade

Scottrade

Etrade

Zecco

First Trade

Share Builder

Interactive Brokers

Think Or Swim

Trade King