I use DSC Colour Labs in Manchester.
They offer some good advice re monitor calibration and printing results.
The idea is to send off a small order to check against your monitor but they will also send you a monitor calibration print and profile CD in advance if required. I'm happy with the results from this company.
A little info from their web site - more from here
http://www.dscolourlabs.co.uk/quality_advice.cfmEditing your Files.
Edit your images in a standard working space such as Adobe SRGB not a printer profile.
Working spaces are designed for editing images, printer spaces are not. From this point you have a file that can be sent to any printer. If you are sending your files to our lab please convert files to our profiles in Photoshop by selecting Image/Mode/convert to profile and then select our profile which will be in the list. For users of Photoshop CS2/3/4 choose Edit/convert to Profile.
For further information on ICC Profiles and colour management etc the following site is very informative
www.drycreekphoto.comAn image that looks bright and clear on your screen should produce a perfect print. If an image is dark and dull on your screen this may produce a disappointing print. Generally, most digital cameras produce excellent quality results these days, without having to edit or enhance the image at all.
The best way to set your screen to our system is to have an order printed and then check that the prints match your screen.Once you have received your prints, adjust your monitor brightness and contrast to get as close as possible to the print in your hand.
If you require a monitor calibration print and profile cd in advance of your first order
click hereClick here to see our calibration image.Hope this helps
Tony