I like to go to the manufacturers websites. Yesterday I used a tile pattern on the Boral site
http://www.boral.com.au/roofing/cad_renders_striata_ebony.asp?AUD=buildingDesignProfessional_Rooftil... . I used this texture on a building I am altering and adding too. The textures and scale are just right when the model is Photorendered without the need to scale or adjust the colours, textures, etc. Very handy.
I save the picture in my job file and then load it from the textures dialogue box in the Material Settings.
More and more manufacturers are now setting up accurate pictures that can be used in ArchiCAD eg, bricks, brushfencing, paint, etc.
A Google search within the Pictures setting can also be very useful for finding materials.
Boral have bricks and paving pictures too from my recollection.
I hope this helps.