I just bought the game, and have not started playing yet. I have a few questions on how the character Development progresses. I understand that you start as 1 of 4 classes and then you become the other ones by doing quests. Is it like Duel Classing in other games, where you get to keep all of your old skills and attributes as well and gain the new ones, or do you lose everything that you previously had? Any info and maybe hints and creating good chars would help out.

Yes you do get to keep all your old skills when you move up a class. the only thing you may find is that when learning magic in one class that may not be able to be learned in the next class. i.e. A wizard can learn stone and sun magic..if he only learns these to level 4 then it is hard or near impossible to learn spells higher than this afterwards.

So it is best to keep a character in the class untill you think he or she has learnt all that you require. I found that its just as well to learn a bit more than you want as your never sure what spells you may need. A guiding rule is to learn level 7 magic your character needs to get to class level 13/14. Being that you can only learn magic at half the level that your class is.

As far as starting characters goes there are to many options to start with, but I can tell you what I started with and it seems to have worked out ok for me:-
Male human warrior
Male dwarf warrior
Male gourk warroir
Male rattling rouge
Female wiskas wizard
Female oomphaz preist

Some people prefer the have, two warriors, one rouge, one preist and two wizards..its all a mater of your choice the main thins is to make sure you have at least one wizard as they are the only class that can learn stone magic.

Hope this is of help to you.