@WienerDiva - I assume your tag is not on yet. They will come to your place AFTER your curfew starts. They won't be intrusive, but you might want to make sure your DC are tucked up in their room, out of the way. It could be any of the next few nights. They were generally nice people, from my experience.
Check if your garden is included, if it isn't, you will have to get your solicitor to apply for it to be included - this could take a few days. Even if your solicitor thinks it is included, it might not be, solicitors can be a bit clueless on this. There is usually no reason for your garden not to be included, particularly as you have children and your curfew is relatively early.
If you live in a 2 storey house they will want to put your machine in an upstairs room that will have reach over the whole house. You need a power point which is safe from being unplugged, so tucked away is better, with somewhere for the unit to be placed, which will have a phone on it. They will occasionally ring you on the phone, so make sure it is somewhere you can get to easily.
If depression hits, and it could do so in the next few days, try to leave your house at least once every two days. If you don’t they will ring your unit to make sure that you are okay, and that the unit is working. It might also prompt a visit by them to make sure your tag is still on you (and not sitting on the unit).
Get yourself some loose trousers, the tag is quite noticeable, and you don’t want tight jeans/trousers. Sadly you will have it on through the summer, but it is water proof so you can go into a paddling pool etc with it.