If I may... the advice you've been given is good and certainly adequate. I would, however, point out a couple of things. Although pulling the weeds and using the weed block willhelp, I'd spray the area with a quick acting weed killer such as Roundup. It doesn't stay in the soil and is reasonably environmentally friendly. Second, kind of in line with what Juggerling is saying... the rocks, pebbles, etc., are going to be almost forever. They would be very difficult to remove if you ever want to. As well, dust, dirt and leaf debris will blow in and in a year or two you will have weeds anyway. I'd recommend that you at least look at some of the wood chip, wood bark, products. Here, in the U.S., they come in many colors, only weigh about 20 pounds per bag (2 cubic feet) are easily removed and cats don't usually see them as their private public convenience... At any rate, best of luck!