When I first got the game, and before knowing which server we were playing on, I rolled an assassin and leveled it to 10.
Combat with an assassin is very easy in the early levels, just mash your attack in whatever direction they aren't blocking, throwing in a combo move if needed. By the time you finish the intro quest to the city you should be level 5 (this is true for all classes I assume) and you are directed to see your trainer in the tavern just inside the city walls. This leads you through a series of quests which server to teach you about basic rogue skills, hide and climb. I used the guides at tentonhammer to get through these quickly (
http://www.tentonhammer.com/node/32758).
Once you reach a certain level with an assassin you receive two stances, Unholy and Poison. I preferred the direct damage boost of the Unholy Stance, but make sure you are always in a stance once you have them as this adds a ton of damage and allows you to take on tougher mobs.
These get you to about level 9, I had to leave the single player night realm to find enough mobs to level to level 10. I found a few day quests and stealth ambushed as many mobs as I could.
After I hit level 10 I found out I was on the wrong server, so I rerolled a Herald of Xotli but I found that to be a weak starting class for solo play so I am thinking about a soldier class at the moment. I'll report back on my next character once I hit level 10.