I have an alpine/nubian doe, a nigerian dwarf/alpine/nubian (her son) and a nubian/oberhasli and the nigerian did learn where all the "holes" in the fence were when he was a kid. Now he's too big to fit in them, plus I put two wires of electric fence in - one about 6-8" off the ground and the other 4' high to deter jumping over the fence, which my larger doe did.
Keep in mind that if you don't want to loose any flowers you might have you will want to keep the goats in their own little yard - or out in your yard under close supervision.
They also love tree bark, so they'll eat the leaves off any trees you have and peel the bark, killing the tree. Any special trees should either be off limits or protected in some way.
Do you already have a barn or some type of enclosure for them? If you're only having 2 or 3 a small 8x12 will work out great. Mine live in a "barn" that size with the milking stand, two hay feeders and the grain bin. They love to jump on the feeders (which are wood ones I made from instructions on
www.goatworld.com and then cut in 1/2 and screwed into the walls) and sleep on the grain bin and milking stand.
The Nigerian's will give you good milk, but their teats are smaller so if you have big hands you'll have to learn to milk with two fingers.
If you choose to keep them in their own enclosure, put some toys in there like a balance beam made from scrap wood or three different sized stumps arranged so they can play king of the mountain. Here's a pic of my youngest doe (the oberhasli/nubian on the left) and my nigerian dwarf (on the right) on their "mountain" last year.
The green tarp "shed" you see is what I kept mine in until we built the 8x12 in that spot. It was a 10x10 dog kennel that I put a roof and tarps on. Suited them well for quite some time - but they needed something more permanent.
Good luck - they are a lot of fun and worth everything!