Granite floor riles

[Regis Quality Tiling]

Hi,
I've just laid 6m of polished granite floor tiles on a bathroom. I was told by the seller of the tiles that I should seal the tiles prior to grouting and also afterwards.
Ive also read somewhere that I should leave it a period of time before sealing and grouting for any water in the tiles to evaporate. 2 weeks was mentioned. Sounds a bit excessive??!!
Two main questions - does this sound right?
Secondly is there a recommended sealer that people use?
Thanks for your help.

 

[Rae]

Suprised ,supplier didnt sell you the sealer ,once before then after the grouts dried