You would have to make about $107k in 2009 to be eligible for maximum benefit. (But would have to make the "max wage" for many years - not just one). All that can get rather complicated.
Here's a link that explains more. Looks like max benefit is currently about $28k/year for a single person.
How much will Social Security provide in retirement? - Financial Calculators from Dinkytown.net
You should get an annual statement that tells you what you qualify for currently, based on past wages. (Though obviously does not tell you much if you are young).
As an aside, I find most people don't have a clue that social security benefits are taxed. It's another one of those "not indexed for inflation" thing, so I find people don't expect it, and are shocked by the taxes, when they retire. Just as a FYI, because I know that so few people actually even know this. Talk about a stealth tax!