I have found that for learning the game, playing a character that is useful to groups and has a good means of stealth/escape is pretty effective.

Some combo's you might want to try

Shifter with Defense or air as one of your foci, def shifters are generally hard to kill air shifters can get away easily.

Assassins. Like AA said they rock, they do well with good gear but are not completely dependent on it, and most importantly they are good at hiding.

Transmuters. Always welcome in a group, and once they get Duo they are very good at avoiding randomly getting killed.

Rangers are good but you need to know and stay in the wilderness (the wiki page is good for this and you will learn a lot about wilderness areas by playing one)

Another thing to remember is that if you are in a high traffic area and fighting odds are someone(or a roving gank) will jump in and try to kill you, your victim, or both of you.

To avoid this I generally either try to land a really quick kill, fight in a more remote location, or come with my own band of merry slayers.