The answer to the second question is, sooner than you think!
Ideally, you should stop by the Office of Student Academic Grants and Awards sometime during your freshman year. Many fellowships and scholarship opportunities have application deadlines from six months to a year and a half in advance of the actual deadline. Your best strategy is to start thinking at least two years ahead.
Applications requiring institutional nomination have campus deadlines up to several months in advance of the foundation deadlines. You must go through the campus nomination process, or your application will automatically be rejected by the scholarship foundation. Don't run that risk!
Virtually all major foundations now make their scholarship applications available on-line; a growing number including Fulbright, Watson, Marshall, and NSF can be submitted partially or entirely online. Program requirements and internal deadlines vary, so before you set pen to paper or finger to computer key, get some advice.
And if you aren't yet well-organized for life after college, come in and visit anyway-there is a wide world of funding and opportunity out there that we are here to help you explore.