qcharts is a good product for beginners. i was a subscriber when i was still at school. my custom software ran originally off the qcharts feed api.
it was a good product back then, late 90s, early 2000's, since all you needed to make lots of money was US stocks and equity indices.
back then their only problem was they had so many subscribers the servers could not keep up.
today, 2006, it lacks significatively, since it doesn't have cash forex, international eq indices/futures (no eurex, sgx, tse) and their data for metals, energy, bonds have lots of errors and there is no adequate continuous contracts charting capabilities.
i went for another provider after they erased their intraday historical data for a few months back in 2002, and I couldn't backtest my system for contracts I hadn't downloaded.
well i subscribed to not have to mantain a database as their sales pitch promised... i was wrong.
their original design is excellent though, charting could not be easier and fast, i don't know what happened they don't care to backup/mantain their data or to add new symbols it almost seems like the qcharts people are underpaid and hate their job or don't care subscribers have money on the line.