All brokerage houses now have web sites and accept orders online because it allows them to cut costs and compete for your business with low commissions. Some on-line brokerages require a significant cash balance, even as much as $10,000, before you can place trades.
Here’s a few web resources with more information:
- The Securities and Exchange Commission offers tips for online investing.
https://www.sec.gov/investor/pubs/onlinetips.htm - Reviews.com published a guide in November 2015 with their choice of 11 best online brokers.
http://www.reviews.com/online-stock-trading/