I was in roughly the same prior-Harry-Potter-knowledge state as you are and I enjoyed it.

It's set in an alternate universe to the actual Harry Potter series, and starts from the events in the first book. You won't miss much from not having read the actual books.

I hesitated to start. Partly because I found the original Harry Potter kind of boring/frustrating. And partly because it's fanfiction, a sort of writing I do not normally enjoy.

Still, I found it enjoyable and worth my time. Even though I thought Harry's portrayal was pretty uneven (swinging between "scientist/genius in an irrational world" and "arrogant prick demigod").

I liked Drako's additional depth far better than Rowling's one dimensional jerk.

http://www.elsewhere.org/rationality/

(rehash of my previous comment: http://news.ycombinator.com/item?id=3231266 )

There are some inside jokes you would miss out on if you didn't know the canonical universe, but overall, like others have said, it can stand on its own as a great work.