I am a bit of a DIY'er so everything I had to learn from here but its not too complicated once you get your head around things.
I got my cat5e cable from cabledirect and the rj45 keystones and dynamix patchpanel from PBTech. They seemed to be the best price/value.
Also find someone with a trade card as you will be surprised by the tradeprice for PDL wallplates, ADSL2+/VDSL master splitters, Gel joiners etc from places like mastertrade.
I have also put in RG6 for SKY/TV around the house and its best if you can do it at the same time.
I was lucky as I had under floor access. Might be a bit harder coming from the ceiling space to where you want to put the network points.