The 3% represents a paradigm. It shows the power of compounding gains over time. That we just need to consistently hit the singles and not try for the double or home-run. When I was first starting out and had only $2 - $3,000, yes, I would invest the entire amount into one stock.
Tools that I use are the setups found at www.stockseasonality.com to look for entries and exits and stockcharts.com to scan for criteria and perform technical analysis.