Potting: I recommend fairly big pots (25 - 30 cm diameter). I have seen clay pots recommended but I simply use plastic pots, which are cheaper. The plants grow quickly in the summer months and can get fairly large. My biggest plant got to about eight foot high, though I just let this one go out of curiosity and there is no need to have your plants this tall. Cutting the plant back will allow you propagate new plants as well as turning the existing one into a bushier, leafier entity. Even so, after a while you will probably need to support your growing plant with a bamboo cane or some such. When potting, place the rooting stem deep in the soil, almost to the bottom of the pot if you can. Remember with a newly potted cutting to keep the soil well saturated at first.
Re-potting: When re-potting to a larger pot, for example, a newly received young plant, remember that re-potting is always a bit of a shock. The plant may not grow for a week or two after this; it may even shed a few leaves or even die back a bit. Make sure your plant has got used to its current environment before re-potting. If it's been recently transported, you should let it settle in for a couple of weeks first. It's quite a good option to take a cutting (or two) before re-potting. Then you have the benefit of the cutting(s) as insurance, plus a sturdier remaining plant, with less leaf to support, better able to withstand the 'shock'. An alternative to this is simply to remove one of two of the bigger leaves, or trim them, as one might when making a cutting (see notes at the bottom of this picture). As with direct potting of a cutting, re-potting should place the stem deep in the pot to ensure a sturdy plant.
Pinching: Cutting the plant back means you get a bushy leafier plant, - in contrast to a tall straggly one. You'll do this naturally in the process of taking cuttings, but remember, even if you didn't particularly want cuttings, you still might want to 'pinch'. Pinching is just nipping off the budding leaf at the end of the growing stem and will have the same effect, i.e. of encouraging the plant to put out new stems lower down.