I came to attend last canton fair in April 2011, I took my flight from Delhi to Hongkong, it was pleasent journey.
After landing to hongkong I didnt' go for imigiration counter but took ferry ticket for shenzen (I wanted to skip HK immigration hassels). From ferry terminal in shekou I took taxi for Guangzhou Heng fu Lu, my regular hotel Dong Yue on Heng fu Lu (there are two Dong Yue Hotels but this is cheaper one) The hotel is very clean and supportive staff, only thing is they dont understand much english, but that is value for money. There are a few indian restaurant nearby so you dont feel like without food especially for vegeterians. For Canton fair you can take taxi, but we usually take metro as it is very convenient. One more thing whenever you are going to Canton Fair you should pre register yourself for fair this will save your money and time. Going to fair (Pazhou Complex) is OK but in the evening there is a lot of mess, all metros and buses are overloaded and there is no taxi available at that time, so if you can manage you should leave the complex half an hour early before closing time that will save you from that rush.
Rest is all usual, you should take care of your passport and money especially on Bejing Road.