In coming across from a point and shoot, another thing to be aware of is that any DSLR (including the K-x) is going to have a different (much smaller) depth of field than your point and shoot, due to the sensor size differences between a P&S and a DSLR.
This means that where you may be used to taking shots wide open with a point and shoot and having foreground and background all in focus, with a DSLR that generally isn't going to happen in the same way, unless you go really wide.
You generally have to be more aware of depth of field when using a DSLR than when using a P&S. This might take some getting used to.
To supplement your reading of the manual
, here are also some excellent general tutorials that I've found very useful:
Digital Photography Tutorials
My other bit of advice to a new K-x user would be to stick to using the 'auto-everything' AUTO PICT mode for the first few days, until you get used to all the camera controls, rather than jumping straight into Manual mode or something.
Oh, and I'd also strongly suggest that you NOT put any UV or 'protection' filters on your lenses. They can really hurt image quality and will cause all sorts of issues that will get you thinking there is something wrong with you or the camera. Just always use a lens hood if you want to protect the front element of your lenses.