You don't say whether you are in Qeynos or Freeport. I can give you advice mostly on the Freeport side.
I agree with Zieveraar's advice above. At 11, grab any and all quests you can do. If you're posting here, then you have access to an excellent reference of most every quest available. Also, try to get as many quests assigned to you as you can before going hunting. Do the delivery quests first. They not only give items and/or copper as a reward, but every quest also gives some amount of xp. It is actually possible to level from 11 to 12 without going hunting. Then, when you are ready, try to get quests which often require the same mobs killed, and you can kill two or three birds with one stone, so to speak. There are some good quests that begin in the Sunken City, for example, that are easily completed at level 11+.
Once you make level 13, I would head to the Commonlands. There are several quests given in the Freeport city zones which require you to either just visit the Crossroads, or deliver a message to someone there. Just watch out for the orcs along the path there. Don't forget to speak to the guys just outside of the Freeport gates, too. Constable Calvin on the left as you exit gives the Front Yard cleanup quest, which people often dismiss, because it only gives 7cp, but it gives decent xp for killing 6 mobs that you will get xp from anyways.. And, if you happen to be doing the speckled snake quest from SFP, or the Armadillo hide shield quest from there too (you should have gotten them both assigned anyways) you can kill the same creatures and get an extra 7c, and decent xp for mobs you were going to kill anyways. Front Yard cleanup is repeatable, too. I still stop by and talk to Constable Calvin every time I pass. I get almost 1% per completion at lvl 19. 6 easy mobs, located close by. It's an easy way to work off xp debt too...
At 13 or so, you should be getting some assignments which involve Wailing Caves. This is great. Experience in here is good through to about 18 or so. Check the site and try to get all the quests involving WC as you can, this is a fun zone. A bit dangerous at first, but once you learn the zone, and get a few levels enough to be safe up top, delve into the jail cell area and further for harder mobs.
At 17, I started the Key to Fallen Gate quest. Talk to Kanos X'Aphon in NFP near the manhole to Thieve's Way. He sends you out to the FG gate area to talk to Tundis N'Oxyle, who then wants you to kill sandstone giants, which are located right near the FG area. This is an excellent example of a mob with which you can finish 3 quests at once. This one requires 5 giants. The Captive's Information quest which starts in Big Bend requires first tortured souls outside of Zarvonn's tower, which is just before the FG gate area, and then requires 5 sandstone giants. And while you are in the Crossroads, if you inspect the axe on the wall inside the tower there, you get Grum's Inspiring Axe quest, which requires 15 giants. So you get 3 quests credit for killing 15 giants, might as well kill 15 while ou're there for the first 5, right? The experience just adds up. But the final part of the Key to Fallen Gate quest is the best. Best to do the whole quest in a group, if you can. At the end, you talk to Kanos again, and he sends you to an instanced zone to fight three floors of cutthroats. There are a few nice items that drop here. Read more about this part here http://eq2.allakhazam.com/db/quest.html?&eq2quest=209
So, to level, I recommend quests, quests, qnd more quests. If you do it right, you can work it out so you're killing mobs which still give experience, to finish a quest that gives bonus experience. And, there's some nice gear and money to be made on the way. Use this site and do the research. Find the quests which involve the areas you might plan to hunt in, and make sure you get them assigned before you do.
Oh, and one other thing. Enjoy the scenery while you travel. Inspect everything that might catch your eye. Sometimes objects out there are the starts of quests as well. And sometimes, just visiting a new area will gain you experience as well. But mostly, just have fun, and be safe. Good Luck!