Concrete help

Right I'm going to concrete some sleepers into the ground tomorrow, they are the uprights for the sleeper wall, they are 900 mm, 300 will be buried in the ground. Once the hole is dug do I need to add any hardcore into the bottom of it? Also what do I need to buy to make the concrete? Any other help or tips would be great

 

I always throw in any odd bits of hardcore i have around the garden, just saves me taking them to the tip,i would use postcrete its fast setting, and its pre mixed just add water

 

I know you can get quick drying concrete thar sets in like 12 minutes

Which is handy if its windy etc but no idea what is called

Just know the guy used it for my concrete fence posts when it was gale force winds

 

If you don't need a huge volume . Its best to buy a ready mixed bag off concrete or postcrete if its a post you are putting in . All the big sheds sell it.
http://www.diy.com/departments/blue-circle-postcrete-ready-to-use-concrete-20kg/35713_BQ.prd