You will need a broker to buy and sell stock. The differences between brokers are Customer Service, Commissions (Per share or per trade), Minimum funding requirements, and Platform fees.
Here are a couple of things you can download that are useful
Some Brokers have platforms for charts, and you can utilize others if you broker does not have a great platform
Level 2 Data
Some Brokers have platform fees that come with Level 2. You can use other sites that have just Level 2 data.
Stock Scanners and Screeners
This excel sheet will help you calculate the share size for the amount of money you are willing to risk. Click Here to Download.
1 Page PDF download for a quick reference.