I would recommend Classic servers. There, the early battlegrounds are semi-populated. You can literally be RvRing the first day you play.
Leveling has been made tons easier. It used to be going from 40-50 took forever, but now, those levels are actually probably as fast if not faster than the 30-40 levels. The reason is because of 2 repeatable quests they have added. One starts at level 40, and most people use it until level 47. Then, there is one that you can do at level 47 and get yourself to 50.
For finding out about these quests, and any questions you have in game, there is a newer chat channel in game. It is an advice channel. Just type in /advice <question> and people are usually pretty good about helping. You might get the occasional idiot who tells you wrong things, but most people who respond are actually helpful.
The game has less people leveling in it than it did when you played last, partially b/c it is so easy to be powerleveled now, and most people care about the end game RvR. You and your brother will probably level together alone most of the time, with the occasional finding someone near your level to join you.
However, for you, I would suggest going to the battlegrounds. There, you will not be at a huge disadvantage (gear wise) and people can not kill lightning fast there. You will have a chance to actually experience fighting. I would turn my xp off and rp's off when I hit 24 if I was you. This is the final level for thidranki, and it is usually very populated, easy to find groups, and a good way to experience PvP combat. The earlier battlegrounds can be some fun also, but I would not bother staying in them for long periods of time.
The best way to get more help is to join a guild that is willing to help new players. Here is a link to guilds, most of them recruiting. I would recommend you go to Gareth, Ector or Lamorak (classic servers), but you are free to go to any server you want (do not choose Gaheris though, and probably not Mordred).
http://www.camelotherald.com/more/3475.shtml
Find one that sounds interesting, create a character there, and give them a shout to see if they will help you out.
I recommend RvRing at level 24 before trying it out at level 50. The reason is b/c at level 50, there are very organized gank groups that roam around. There are things they know that you will not know and they can kill incredibly fast. It can be discouraging for newer people, but you have to realize they are in Ventrilo or some form of team speak, have played together, and understand the game and its nuisances..you may be able to learn some of that in the battlegrounds on your way to 50.
Edited, Mar 19th 2008 9:18am by thuri