Ticker symbols are letters used to uniquely identify a public company, such as AAPL for Apple.
Knowing a company's ticker helps you retrieve company info quickly.
The ticker symbol can be found in Mergent Online, Business Insights, many corporate reports and at free websites like Yahoo Finance or MSNMoney
These sites provide summary information for recent filings with links. Check SEC for all S-1 and IPO filings.
Some sources below include IPO pricing performance data.