In the US there is NO legally mandated paid holiday time, and no maximum work week. Any paid vacation is at the discretion of the employer, as is sick time and any other worker benefits. Legally, an employer only has to withhold for social security (i.e. pension) and state and federal income taxes. There is no obligation to offer health or life insurance or any other benefits.

In practice, most employers will give you two weeks (10 working days) a year. This may be increased to three weeks after 5 or 10 years of employment at the same company. If you change jobs, you start over with the basic two weeks unless you negotiate something special with your employer.

And the working hours situation depends entirely on the company. In Silicon Valley, fr'instance, 80 hour weeks are not at all uncommon, especially when you're working on a "hot" project. You work to get the job done, not by the clock. (With most IT workers on salary rather than hourly wages, there is no overtime pay. You may be eligible for a bonus or stock options, but these aren't necessarily related to how many hours you work.)

In some companies, there are those who brag about "never" using their vacation time. It is often seen as a true sign of the "dedicated" employee.

Admittedly, when you're in the middle of it all, it doesn't seem nearly as awful as it does written down like this. And things vary considerably from one employer to another. It really pays to get some feel for the "culture" of any company you are considering working for.
Cheers,
Bev