How many days do you take out some water and add too or is it once a week and do i leave the water in a jug for a few days before hand? or do i buy somthing to treat water etc 

If the tank is all set and cycled I do a 15 % - 20 % waterchange per week. Once a month siphoning the gravel and a 50% waterchange, aslo trimm the plants, maybe add new ones, check the filter media.
Watertest once a week.

If your tank is not cycled you should test your water daily and perform 50% waterchanges accordingly.

Always add waterconditioner and check for pH before adding the fresh water. Also adjust the temp.
You may need to add beneficial bacteria too.

Before adding fish the tank should be cycled anyway.

The nitrogen cycle has been explained ten million times on this forum already, it's a ca 6 week process where the bacteria nitrosomas are established in the system to deal with ammonia and nitrite. In the first phase ammonia is rising to slowly disappear and turn into nitrite which in turn will give way to nitrates, which would be the final stage of the cycle. In a cycled system the nitrates will slowly rise, and the ammonia and nitrite are both 0. You deal with the nitrates by regularly changing a part of the water.

And I would recommend nothing less than 50% every week in an established system. Anything smaller won't help the slightest in the long term.
It's important to clean the gravel with a siphon as well, during every water change, so if you don't have a gravel cleaner yet, go buy one! They should be real cheap since it's pretty much just a cup on the end of a hose d:

You don't have to leave the water to stand at all, that's just some bullsh*t. Buy a good water conditioner and dose every bucket of new water with that and it'll be ready to be poured into the tank right away! It's not any more complicated than that

Hanna: Thanks for mentioning the plants! I take it for granted that everybody have live plants in their tanks! xD

I think the problem is that it sounds more complicated than it is. You mentioned that neighbor of yours who was completely turned off just because she heard about the nitrogen cycle and decided not to keep fish after all. But it's really just about watching the water quality for a few weeks! And the plants? Well, they take care of themselves. I don't know how many times I've read in books and on internet that they're messy and need to be looked after. I've pretty much just planted them and left them to grow during my years of fishkeeping d: It's enough knowing that they absorb the nitrates from the water and gives oxygen, lol.

Btw, I bought a load of new plants today! But there are a few I'd like to buy more of, so I'd still like to wait with posting pics

That's the exact reason I don't have plants. I always thought they were too hard to keep and I have been scared off until now Though I am still a bit scared as I'm a total newbie to them But I've done a fair bit of research so hopefully all is ok.

ah thats so i dont have to move my fish into a bowel to clean the tank iv have a fluild to help make the water safe for fish do i just keep adding and taking water

I'm not sure if I understood you correctly, but during partial water changes, you leave your fish in the tank, and change just a part of the water, about half per water change is a good way to go
And yes, a water conditioner that will neutralize chlorine is needed for the new water, you dose each bucket for the amount of water it contains, and then you simply pour it into the tank But be careful when pouring so it won't uproot any plants

In conclusion: You remove half of the water in the tank (and clean the filter media in the buckets of water if needed) and then you fill the tank up with new conditioned water

Anytime It's good that you ask!