you probably don't have enough money to warrant a broker. lol They take a cut and probably won't deal with you unless you have 25 or 50k with them anyway.
right now, i'd stay out. The market is super inflated right now and a pull back is basically eminent. I'm in because its still going up, but i watch it every 5 min with my finger on the trigger.
instead of dumping in, i'd consider taking this time (the next month or two) to research some companies. See what their financials look like. what new products are coming down the road. etc etc
You can trade a couple ways. one, in a regular cash account. any gains will be taxed at prevailing capital gains tax rates (30%). put in 1k, now its worth 2k, pull out, you have 1700 after taxes.
The other, which is the way i do it, is with retirement accounts.
fund a roth ira or even traditional ira with a place like fidelity.com and you can use their cash account that pays penuts or put funds into stocks, mutual funds, etf's, etc...
anything you earn on a stock is not taxed to you at the time you sell it. instead, it simply goes back in to the 'cash' holding of the account. You will only be taxed per the ira format when you disburse from it at retirement.
the 'best' investment is one that makes money. That changes hourly, if not minuetly. Diverisifcation is key.
put a little in a lot of places.... within reason.
There are sectors (ie, finance, tech, industry....)
There are caps (mid cap, large cap) which relates to how much a companies total stock is worth and denotes company size/value
There are domestic and international of all 3.