I play around $3500 a stock. sometimes less sometimes more. The penny stocks are super risky so you have to use sound judgement and do your reasearch, true research like find out who is behind the company and try to see if anybody on the boards has info.
These are the type of stocks that if you sell on the open market you might drop the price 10 or 15% so there is a lot of volatility. and same with buying a stock. You can literally sell a thousand on the open market if you can read the level 2 quotes jack up the price create a little buzz and then make a few posts on the boards and make 30%.
I buy some large caps too. I have some BAC and C that are just going slowly but10% and 15% are better then anything.
In Canada we have an excellent tv station
http://www.bnn.ca/ they have excellent advice and guests on there. I also peruse stockhouse.com