There's a "right way" and an easy way.The "right way" is to dig a 10" channel, fill it with 8" of compacted mixed-gravel, build your borders (wooden or concrete curbs), add an inch of compacted sand, and lay your slabs on top of that. Doing this will give them the best durability. It was hard for me to find a guide online, but this FAQ will hopefully give you a few answers: http://www.bolduc.ca/frequently-asked-questions.aspx#FaqQuestion16The easy way is to simply set them on top of your grass. It won't be as durable, it won't look as tidy, and a few may rock... but it should last a season or two. This is perfect if you're renting as the only damage is some dead grass.