I find high cap stocks with large range and low beta to trade on longer intraday time frames like 15 and 30 minute.
Then I'll trade smaller cap high volume stocks to "scalp" on 5 and 1 minute frames such as AAPL, GPRO, QIHU, etc.
BioTech is pretty popular among traders I know who have professional experience. Anything with volatility as well. Earnings, IPOs, mergers and acquisitions, etc.
If you want to keep up to date, download ThinkOrSwim and on the left panel that has your watchlist and account information, open up the "Trade Flash". It'll keep you up to date on what's going on. Large prints on stocks, 52 week high/lows, imbalances, etc.
13:46 X 52wk highs
13:32 crude almost a dollar above pivot /CL
13:32 SHLD -8.56% 52wk lows
13:29 TSLA highs
I'm not sure if every platform has something similar to this, but I like it.
I also suggest websites such as StockTwits.
I use filters within my platform though. Stocks that are +/- 3% or greater with 100% more volume than their average. Besides that, I just scalp AAPL and TSLA throughout the day.