The best thing for calibrating your monitor is a dedicated hardware monitor calibrator like the
Spyder range. However, I design stuff for print and in 17 years I've never had any major problems with colour reproduction when using
Supercal for the Mac which does a pretty decent job. I'm sure there will be similar shareware out there for the PC.
Unfortunately LCD screens vary greatly in their ability to produce good colour. There are 3 main types of LCD panel.
TN panels (twisted nematic) are found on most of the smaller (22 inch and under) and cheaper lcd flat screens and most laptops. These are the least impressive for colour reproduction as they are unable to display the full 16.7 milion colours and instead use dithering to make a 'best guess'. They also have a habit of being very poor when viewing from any angle other than straight on and have a habit of over saturating colours, particularly red.
Next best are the VA (vertical alignment) panels which include PVA, S-PVA and MVA. These are pretty good and can display true 16.7 million colours but while not as bad as TN panels can still produce slight colour shifts when viewed from an extreme angle.
Then there's the daddy. The S-IPS panel (in plane switching). These are THE monitor to have if you're a graphics professional. Great with wide viewing angles and stunningly accurate colour, just as good as a quality CRT. Seriously expensive though.
EDIT: photobox are good. The photographer at the newspaper I worked at used them all the time and we've never had anything but good quality, fast turnaround stuff from them. Never used their large format service before but if it's as good as their regular stuff then it'll be good quality and great value.