Honestly, don't try to misrepresent yourself as someone you're not. If you haven't done DC work before, don't try to make it sound like you know what you're doing -- when it comes to doing the job, they'll assume you have knowledge you don't, give you some job you can't do, you'll stuff it up and you'll be thought of as incompetent (or dishonest).
Instead, in the interview, highlight that your skills are self-taught, and that you learn really fast. If they're really after an entry-level position (rather than, say, an experienced tech they want to pay entry-level wages for), then they'll understand that the right applicant won't know what they're doing, but will be able to learn quickly -- something you should be able to demonstrate.
For an entry-level DC tech position, the questions I'd be asking would be the sort that would examine the candidate's ability to both follow direction and learn quickly -- past jobs, education, that sort of thing. Given the job is largely physical in nature, I'd be inclined to give them a practical test -- say, a pre-wired (not perfectly neat) half rack and some (decommissioned) servers and networking gear, and get them to audit it. Attention to detail, accuracy, and speed would all count. Then probably give them a few change requests ("recable port X-Y to port Z-AAA") and ask them to execute them. They can ask whatever questions they feel are appropriate, and I'd give reasonable supervision (they're entry level, after all), but it's mostly about their ability to listen, ask reasonable questions, and learn.
For an experienced DC tech position, I'd have the servers in a pile on the floor and tell them to go rack it all up. Neatness, speed, and accuracy count for the most in this situation, and while questions are allowed, if they're the sort that show that you're a web developer who's trying to bluff me into hiring you as an experienced DC tech... <grin>
