wii hacking question...

Ok-after some thought I'm considering hacking my wii earlier than expected.However-I only had experience with a psp and flash cards.So how does it go-is it firmware or just a unofficial channel that runs programs that it's not meant to run?And...can I update the console for future releases or will that brick the system?

Well, it depends on what firmware you're on right now. And if you do manage to softmod it, DO NOT update your wii until someone releases a safe way of updating (a guy called Waninkoko usually comes up with a safe upater right after a new firmware release). So what firmware are you on?

4.00E currently-last check it was suitable-but I may go past it in the future...CHristmas is coming-new games to buy you see XDHrm...not advised...Any way to revert back just in case?

Only way to revert back is to soft mod it first. But you can still do it at this stage, but I'm not quite sure how. I did mine a long time ago, and things have changed since then. I think there's something called Bannerbomb which uses a code overflow to make the Wii run some code to install the "homebrew channel" (your portal to all Wii modding), but you'll have to do your own research into that, or find someone else. Sorry, but that's all I know. But another thing, you should be careful to find a detailed guide and follow it step by step to avoid bricking your Wii. But it's worth it, in my opinion.