Over at Suvudu, Del Rey VP & Editor-in-Chief Betsy Mitchell has been writing a (mostly) weekly column about publishing called "What I Learned This Week". In this week's post, Betsy discusses bad cover letters on unagented submissions. Really, really, really bad.
This ties in very nicely with A.) Moonratty's awesome post about unagented submissions earlier this week, B.) Nathan Bransford's comprehensive and educational post about what not to put in a query letter and C.) Jennifer Jackson's very smart contributions to the same subject today.
To sum up: Write queries that do not suck.
That is all.