if you dont have a main character yet, use the "skip the fun" feature on the character website, and just keep trying different class till you find the one you like
You can do this if you're uncertain of what you want to be. If you already know what kind of type you want to be then I suggest you look on another threads that tells how you should choose your stats and so on.
I'm not saying you should follow them all the way. But only so you know the basics of what you should get and what you should not get.
For overall tips & help can you find the link posted by Joelturuz.
My only major tip is that.
Don't buy too expensive gear early on.
While in the beginning phases do you want to still gain plenty of gold so you can buy all your gear you need.
So don't buy something really expensive early since that will slow your income down.
You should rather make a full set of basic gear. i.e full leather a weapon worth 2-5k, and so on.
Then you just play with it. And this gear should be enough to be decent. Later when you have more gold so can you switch to mail if that's what you wish.