If you are looking for a way to mentor students, there are a number of various resources to get you started. Being a student mentor can be both time consuming and rewarding, and if you are a professional it can help you in your career as well.
Students that need mentoring can be found at all levels, whether that be inner city kids or young adults in high-school that are looking for a career choice. You can get involved in programs that help with mentoring through youth services groups, or you can take this task upon yourself from a wide variety of websites that have been set up for this activity. A simple internet search of student mentoring programs will overwhelm you and give you a wide variety of options to choose from.
I've discovered a newer website that focuses on the mentoring aspect for high-school and early year college students. The concept is to help these students choose a career by being mentored from a broad range of professional occupations. The website is in a current beta program, so I'll refrain from identifying that particular site (hint: look at the url in the link I've identified above for the sites name). I've been able to catch a brief glimpse of the site, but it's hidden now for their beta test. The plan is to open this up in late June or early July of 2013.
They have a good post about Choosing a Career, and if you find yourself in high-school or college and have yet to decide what you want to be when you grow up, take a look at this post.