You may find the forum on RV.Net more useful than this one. I note there is one called roads and routes, 30 thousand topics, over 200 thousand posts.

http://www.rv.net/forum/index.cfm

Well renting an RV and doing this kind of all around trip is just amazing! sounds like lots of fun, I actually have a friend who did that but only to the states (around california) and it was just something that he will never forget.

Give your rough budget and the things you need to cover I would recommend a couple of things:

(1) research, research, and lots of research about your route and where you can park and all.
(2) CHECK YOUR INSURANCE!!! a lot of people are not aware of what kind of insurance they are covered under or is included in their credit card for example.
I would try this site (https://insureye.com/insurance_toolkit/credit_card_comparison) this is a tool which enable you to actually see what your credit does and does not cover! very useful, i tried it before I travelled this year, and honest, its just useful!
If your credit card sucks (which was my case) then just get one that has excellent travel insurance benefits and use it on your trip, be smart!!

Cheers,
and I hope all this helps.

have a great trip!

Have you traveled with these 5 people before? Six people in an RV for over a year is a lot of closeness and togetherness, even for good friends.

I expect you all may not be friends with each other by the time this ends.

Or maybe by the time it starts.

I just got back from a 3 week / 7,500 kms road trip along the Rockies from Alberta to New Mexico. More like a trip around the block compared to what you have in mind.
I did a few similar trips with friend(s). This time I went on my own and it was fabulous.
Aside from technical problems that can occur in the middle of nowhere, six people in one RV for one year sounds like the beginning of a horror story.
I guess the biggest obstacle to overcome will be morale on board. X out of 6 want to stop at that park and explore, the rest finds it boring. X want to do that, Y want to do other things. No. 1 needs a real bed after one week, No. 3 throws a fit because there is no soy latte frappucino in eastern Montana, and so on.
You will find tons of good advice on routings, technical issues etc, and all of that can be solved with money and patience. But unless you and all your friends are really low-maintenance I doubt you will last one month.

I would rather eat glass than sign up for that trip....

I concur with those who suggest the social relationships will likely be the most challenging part of the trip. Before you get too far into your planning, get everyone together for in depth discussion about "what would we do if..." and make the rules clear. What if someone left midway out of choice or necessity, leaving the burden of costs on the rest, or mechanical issues or weather required a shortened itinerary--how do you decide what to leave out, etc. This exercise should not only set the ground rules but also give you a feel for how you would work together while there is still time to change your plans. A shorter trip together of a week or so should give you a chance to sort out some of the issues also. And expect problems. No group of people can live together for a year without conflict, let alone in close quarters in unfamiliar surroundings. I find two weeks even with a very best friend is about all I can handle without getting cranky.

But a wonderful trip if you can make it work.