Potatoe questions ??

Morning all, as some of u will know were or complete novices. We grow in pots and planter. We bought some potatoes back in august and followed the instructions, and now the planter is full of compost and the plants seam to b taking the world which I believe is good  my question is what happens next ? Please don't laugh to much but we've never grown anything before. Ok u can have a little chuckle  I've been told lots of different conflicting things, cut them down, leave them, they need to flower and so on !!

And one more thing wot is the difference between earlies main crop. Is it just the time of year or the variety
Thanx in advance
Ian

Thanx for the reply. We have them in a polythene tomato plant cover. How long after they have died off do u harvest ? We have two planter bags, could we use one and leave the other for a bit longer ?
Thanx again
Ian

Thanx again, sorry for the daft questions but we have to learn some how, and with the amount of knowledge on here u make it easy to learn