I'm using as my main camera a Panasonic Lumix DMC-FZ50 as i like the quality of the leica lens and the 10.1-megapixel high resolution.
you can see camera details here.
http://www.dpreview.com/reviews/panasonicfz50/
Don't just throw the instruction book in a drawer

Another good piece of equipment to have is a reasonably sturdy tripod to mount your camera on.
I find my images look better if there is a plain uncluttered background surrounding the plant with nothing to distract the eye from the plant. Backgrounds do not need to be anything elaborate i use a simple piece of black cloth to stand the plant on.
The set-up

To be sure to get the whole plant in focus i use the aperture priority mode and set the aperture to around F8 (the bigger the "F" number the wider the depth of focus) in dull or low light the camera will compensate by setting a slow shutter speed to gain correct exposure.
Slow shutter speeds lead to what is known as camera shake making the image blur which is where the tripod comes in holding the camera steady, at slow shutter speeds even the slight movement caused by pressing the shutter button can cause slight blurring so to be sure of a still camera I set the self timer to 2 seconds before I press the shutter button.
Once the image is taken (you might want to take several at different angles) download to the computer and have a look at a decent size on the monitor (I can't tell if I have a reasonable shot on the tiny camera screen) If you are not happy with the image go and have another go, digital images cost almost nothing to take and bad ones are easily deleted.
You paid a lot of money for the camera don't be afraid to use it, the more images you take the better the chance of a good one, with rechargeable batteries and the cheap cost of memory cards the cost of shooting images is next to nothing.
happy snapping
hob