How much should I bring with me?

I've been thinking about what I should pack when I move to England and although I am not bringing any furniture I was wondering how much should I pack to bring with me? This is my plan; I plan to check in 1 large suitcase, 1 medium suitcase, a small suitcase that rolls, and a duffel type bag. To carry on I was going to have my usual backpack and hand bag (purse.) Do you think that would be way too much for check in baggage?? When I go to England for 6 months I usually check in just 1 large suitcase and a duffel bag. I've never brought any more than that so I don't quite know the limit. I know that there is a weight limit but is it a weight limit per bag/suitcase or a certain weight limit that all the check in baggage put together cannot exceed? How much does it normally cost to check in extra baggage? Even if I do bring all those bags that still isn't going to be all the things I plan to bring across. My dad who is coming to my wedding in October, I am planning on having him bring a suitcase full of my things. Also my friend who might come to the wedding, I'm planning on her also bringing a suitcase full of my things that I am going to pack and have ready for them before I move. Thanks for any help you are able to give

Hey Princess-
Baggage allowances may vary depending on the airline, but generally you are allowed 2 pieces of checked luggage not exceeding 70 lbs and one carry on plus your purse. They also have dimension requirements.  Here is British Airways' for an example: http://www.britishairways.com/travel/bagchk/public/en_us
Check the requirements of whatever airline you decide to fly on for their specifics. Hope that helps!

If there's stuff you don't absolutely need to have right away, you might be better off (depending on how much the extra baggage cost is) just packing it up and mailing it to your UK address by surface mail.  That's what we did with a lot of stuff like extra clothing and stuffed animals (I moved 2 kids) and household stuff we wouldn't need right away.  We posted it about a month before we left, so it arrived just a few weeks after we did.

And if you're taking books - look into the M bag at the Post Office.

peedal,
did you use US Mail?  how expensive was that?

http://pe.usps.gov/text/pub51/51tblc.html#_Toc498745158

UK is rate level 3, economy mail is down at the bottom. You can also go by the post office and they'll give you a booklet about shipping internationally.

It's been over 1-1/2 years, so I don't really remember how much it was.  We packed up two HUGE boxes we got from a storage company and sent them by surface mail.  I want to say that it cost under $100 - but I'm not sure.  Best thing to do is consult that link from Missy.