If you are a new requester and have never read the Amazon Best Practices Guide, you should take a look at it.
I am not the biggest fan of the customer service that Amazon provides for requesters, but this guide offers a good starting point for new requesters. These are the basics for starting on Mturk and it really is in your best interest to read the entire PDF and understand what it means.
The reason I am posting right now is I just witnessed another new requester who's reputation is going down the tubes as I am writing. They committed many of the same errors that Lighting Buff did and in the last two hours I have watched their ranking drop like a rock.
They published over 15,000 hits in their very first batch, and waited over 6 days to approve/reject hits.
They are rejecting roughly 5% of all hits submitted and the negative reviews are flooding in. Hopefully this requester will be able to catch this in time, but they really needed to read this document and this blog prior to posting their first hits.