OptionsHouse is a reputable online broker. I haven't used them personally, but I know people who do and they have no complaints.
A social security number is needed for various reasons, the primary one being a tax identification number. The IRS needs to ensure they get their cut of your profits.
If you are starting with little knowledge about stock options get educated. Grab a book or attend a seminar or have a look at the internet for the huge amount of FREE information on options trading like http://expertoptiontrading.com/amember/g... .You need to get your head around terms like call options, put options, put bull spread, bear cal spread and my favourite the protected covered call. These are only a few of the options trading strategies there are many more.
Well, I am not going to suggest any online stock trading site until you don't have proper understanding about this business. First go through from proper guidance material. Try this course http://amzn.to/1vDGhot . I am sure this will help you definitely in by explaining each and every aspect of trading options business.
They want a Social Security number to trade. Why? Does anyone reading this use options house? Have you occurred any issues?