I am intersted in travelling around the USA maybe next year and want to know the best way to do this?

I am from the UK and want to know how much money would I need if I travelled the USA for 6 months on a budget?
I want to definitely see New York City but what other places should I visit and how is the best and cheapest way to travel around the USA from New York City, is it by Plane or Bus? I will be on a budget but I want to have a memorable time.

I'm not sure how tight your budget is, but regardless, please do not make NYC your main destination! Certainly it is a wonderful place to visit, but most Americans do not live like that (nor would many of us choose to!) The United States is a huge country! Keep in mind it takes about 4 or 5 hours to fly from coast to coast! The best way would be by car, but that likely does not fit into your budget. Going by bus is certainly the cheapest way (Greyhound.com would be the website to go to) but I wouldn't discount air fare bargins for a long across the country.
I just really hope you get out of the big cities at least part of the time and see what America is for the majority of Americans. The so-called "fly-over country" is some of the most beautiful with some of the nicest people you'll ever meet!
Enjoy your trip!

Where else do you want to go? I might head down the east coast and check out DC there is so much to do there and several wonderful sites to see. I might also check out some other east coast towns like Boston, AWESOME city. Then head down south and check out Savannah and St. Augustine the oldest city in the US. Then head out west and check out New Orleans, Dallas, Phoenix, San Diego, LA, and some other great cities along the way. There are just way to many great places to mention in the US. You might also want to see the Grand Canyon, Sedona, Arches, Yellowstone, Zion, and Crater Lake National Park. All of them are full of beauty and really show the different parts of America. We have some AWESOME national parks here; I really would suggest on visiting a few while you are here.
http://www.nps.gov/archive/parks.html
http://www.usa.gov/visitors.shtml

Bus is probably going to be your cheapest way to travel. Greyhound is our largest company here and serves almost all of the US. However sometimes you can get some good deals on the train and well that is just a cool way to travel. Amtrak is the major train company that goes cross country. To get to some places you might want to think about renting a car….this really would be the ideal way to see the country, but renting a car for 6 months is going to be way to expensive so it might just have to be a here or there thing. You can find good deals if you do a little searching online, always ask what discounts they offer you never know. Center airlines offer great deals between their hub cities like Chicago and STL, a one way ticket sometimes can be found on the internet for as low as $49 so you might want to check into flying from certain cities.
http://www.amtrak.com/servlet/ContentServer?pagename=Amtrak/HomePage
http://www.greyhound.com/home/

As for saving your budget on room I would totally check into couchsurfing. This is the best site that I have ever found for traveling, it is a site that connects other fellow travelers to you. These people are willing to open their homes to you for free. You can search people’s profiles and then request to search on their couch for a few nights. Great way to meet the locals, and save cash. I have surfed and I have hosted and I have never had a bad experience. It really is a cool thing and I have met all kinds of great people. Some people might not have a couch but are willing to meet up to show you the town, or for coffee or whatever. I think this could really help you on your trip and some of your transportation problems. You could have places booked before you even go! You can read reviews from people who have met the host or stayed with them, so you can find someone that matches your personality. Here is the site it is free and very easy to use!
http://www.couchsurfing.com/

Another cheap way to find rooms in the US is check out hostels. They have several in NYC and they are way cheaper than even the “cheap” motels. You can rent a bed in the dorm room for like $20 a night! Can’t beat that and well it is a great way to meet some people. I really enjoy staying in hostels we have some pretty good ones here in the US, nothing like what I have stayed in in Europe, but they are good. At least if you stay in a hostel you can cook some meals in, eating out gets very expensive so look into places with at least a microwave so you can heat up some food and save cash! Here are some sites for US hostels; I think you will find them cheaper than most motels:
http://www.hiusa.org/
http://www.hostels.com/
http://www.usahostels.com/

Get very good at using coupons. Contact the visitor’s center for each city you want to go to and ask them to send you their free visitors guide, it has maps, attraction information and coupons which save you cash. Look on websites for coupons you can print hey %15 of dinner is saving something. They also have coupons for attractions every little cent is going to help you. If you do decide to see the National Parks look into their Passport Program, again saves money. Hate to say it but, I would over budget at about $1500 a month depending on how you plan your transportation and lodging. If you stay at some of our cheaper hotel chains like Motel 6, Red Roof Inn, and Super 8 they usually run about $40 a night depending on the area and what is in town. Well I hope this helps you, I think you will enjoy the US and hey 6 months gives you time to explore some really cool places and see how diverse this land is. If time allows I totally would go up to Oregon and Washington beautiful states!