I tend to buy from my local pet shop. They'll get it in for me if I buy a full sack. They generally supply me with Bucktons. As for prepping it, I chuck what I need into a cool box and cover it with boiling water. Make sure that it's well covered with water and add a bit extra water. Give it all a good stir, put the lid on the cool box and leave it for a day or two. I certainly don't faff about boiling the bejesus out of it these days.
Don't throw away hemp water (water hemp cooked in). It's the best additive out there. Use it to mix grounbait, soak pellets, pumping expanders or hydrating boiles. If not needed put in freezer bags and freeze until needed.