It depends on how many prints you envisage mounting really.
If you only want to try it out then you could buy a ruler type mount cutter like the Logan Team System you will see here if you scan down
http://www.daler-rowney.com/content/logan
However I bought one of these and found it a real pain to cut accurate mounts and very slow and often over or under cut. Eventually when I decided i was going to be mounting lots, I bought the Logan Framers Edge see on same link as above.
This is expensive but I am glad I bought it in the end.
The things to consider with a mount cutter are
1) You need to make sure your mount is square and so an edge at 90 degrees on the cutter is essential
2) Having a guide to know when to start and stop your cut will avoid over run of the cutter
3) Easy to cut bevelled and straight edges
4) Consideration of the max size mounts you are likely to need
Worth watching this video, there are many more on youtube that give instruction on Logan cutters so try and watch them all it will help with your decision
http://www.youtube.com/watch?v=QU_tzQaSPmk
You need to decide what mount board you wish to use, there are many different types colours and textures, some with different core colours. I would suggest starting with a white card and a white core but sometimes a black core can look nice.
I have standardised now on textured white with white core.
