Good resource/advice on mentoring undergrads As a graduate student I will mentor some undergrad students so that they can help me with my work and get some useful experience working in a lab.

From my past experience, I realized that they lack knowledge. So I do not want to them work on data analysis at least for a semester (unless they show promise) but at the same time do not want to just work on tightening nuts and bolts.

Also they lack time to get up to speed on doing research on their own.
What is a good way to get them interested in learning more? Also if you can point to some good resources on mentoring that would be helpful.

Edit (following eykanal's comment): I do not need to interact with undergrads on a regular basis. So I am not thinking about getting them interested in research, in general. I believe most of the students, who come to work in lab, are in general interested in learning, ignoring few who are just want to beef up their resume.

Last time I worked with a student, I had assigned him some data analysis related work only to realize later that he was more interested in working in the lab then in front of a computer. Lesson learned the hard way, because we ended up wasting time.

What I am looking for is the missteps to avoid when mentoring a student so that they would stay interested and try to do things on their own.
All of the below stems from my own experience mentoring and working with undergrads, both as a grad student and as a postdoc.

Firstly, realize that many undergraduate students aren't ready to do research on their own when they first arrive in a research lab. (Heck, neither are many graduate students...) Additionally, many will not want to do their own research, but they're very happy learning what you do and helping you set it up and work through it.

That being said, you'll want to start with simply talking to them during the interview process to determine what they want to gain from the experience. Most won't have a solid answer, but for the few that say something like, "I want to improve my MATLAB skills," or "I want to gain experience doing cell cultures", you now know whether they're a match for your lab.

The majority don't have specific interests, though. For those students, consider allowing them to work on a variety of projects with multiple graduate students. This allows them to observe different research techniques, different approaches to solving a research problem, and the different tools used in research. If you have the time, you (and the members of your lab) can take a more hands-on approach and actively mentor the student, showing them the various steps involved in constructing an experiment and the logic behind the data analysis stream.