One of the most commonly used phrases I have heard throughout my years of being in print and as a photographer is 'It doesn't look like it does on my screen'.
So many people use their computer screens straight out of the box, with no thoughts about calibrating for their specific requirements and that means that the likelihood is they will not get the colour reproduction from a high quality printer that they expect.
Whilst a cheap screen will never have the ability to be colour faithful, these days most monitors over the £200 mark should be capable of getting reasonably close.
It is advisable to purchase a monitor calibrator such as the X-rite ColorMunki which is very easy to use and set up, allowing you to save colour profiles for web or print use.
I have an iMac, a MacBook Pro and a Dell Ultrasharp 25 monitor and all three are producing a result that is indistinguishable from the other. It makes life so much easier when working across multiple devices - which I find I do most of the time as I take my MacBook on location, sometimes editing images on the road.
Added to that using the correct colourspace makes a huge difference too. The spectrum of colours produced by the printing process is narrower than those that we see on screen, therefore an adjustment has to be taken into consideration when preparing files for print.
Without going heavily in-depth in this post, I will give you a very useful link below which explains in detail, how to get the best out of your images in their 'From Camera to Print' series.