You start out in Greater Faydark. First, locate your Guildmaster. Hand him your note and then by Burst of Flame and Snare. Head out to the newbie section off of the "newbie lift."
For the first couple levels you should hunt bats. They are easy to kill and do not swarm. You can try and take out a giant wasp drone but if you do be careful because these are social and do swarm you. The bats often drop batwings which can either be sold to vendors in Kelethin or people auctioning to buy them in stacks.
Now kill bigger newbie mobs such as wandering orcs, pixies, and widow hatchlings. Be careful with the pixies because the guards do not kill them if you bring the pixies to them. Continue to sell in Kelethin.
Now head back to Kelethin for your level 5 spells. The major spells you need are Burst of Fire, Grasping Roots, Whirling Wind, Gate, Camouflage, and Harmony. After you buy those and you have enough money to buy more buy these minor spells: Invoke Lightening, Cure Poison, and Cure Disease.
At level 5-6 you have two choices. One can be to head over to Butcherblock. There you can kill wandering monsters such as giant bats, giant snakes, etc. You will sell to the people in the huts that are close to Kaladim. Or go to the Orc Lift and either kill wandering orcs such as pawns or conscripts. You could also form a group and camp the orc hill. This can be dangerous so have your heal, buff, and direct damage spells up. The hunting here is good until about level 9.
Return to Kelethin once again. The major spells you will need are Ignite, Light Healing, and Shield of Thistles. The minor spells you don't need but are nice are Enduring Breath, Firefist, Treeform, Strength of Earth, and Thistle Coat.
By level 9 the orc hill in Great Faydark shouldn't be giving very much experience. Zone into Crushbone and start by finding a well and balanced group to camp trainer hill. The trainer is red to you but with a good group you can take him out. He drops a shiny brass shield which you can probably use unless you have gotten something better.
You are now ready for the slavers. In this area you should get a group and have them pull slavers from inside a dirt sort of mound. If no slavers are in there then have them pull legionnaires from around the castle. The slavers drop keys which can be used to free slaves. Just give the slaves 1 copper and they will tell you which key they need to become free. Give them the key if you have it and you will gain nice faction with their respective races. Watch out for Rondo Dunsfire. He is a mean NPC dwarf and you are KoS (Kill on Sight) to him.
You ought to hunt at the two bridges, generally in a group (For the simple fact that trains come by there, and it is nice to have someone help you with that orc that thought that your meditating was bad.) When you get bored of this, you can cmap the Throne Room. BE CAREFUL!! This is a definite group area. DO not solo. The trains are hideous and watch out for Three people: The Prophet, Ambassador DVinn, and Emperor Crush. They tend to be trained from the tower, and don't really like you.
Now you start to get some nice helpful spells but the cost gets extreme. Buy Bind Affinity, Cascade of Hail, Summon Food, Summon Drink, Levitate, Skin like Rock, Stinging Swarm, and Spirit of the Wolf. The minor spells are see Invisible, Befriend Animal, and Halo of Light.
At level 14 you have many many choices. If you want to find more races and meet new people then head over to Oasis of Marr and hunt crocodiles. There are all different races hunting there. You can sell at a gypsy camp. Watch out for roaming sand giants because if one gets on you it will beat you to death. If you want to stay close to home then hunt stuff in Butcherblock that consider around your level. If you want to level fast then go to Lavastorm. First bind yourself at the Najena entrance. Then kite (cast snare, run and cast direct damage) mobs back to the entrance and if you ever get into really bad trouble just zone. The experience here is great and you almost never die because a zone is always accessible.
The best place to go now is Lake Rathetear. Get a camp spot on Jonah Brucker. He is a level 15 monk (location -942,2418). The spawn time is 6 minutes which leaves you enough time to meditate and heal up. It is great experience, you will level extremely fast.
The spells you will definitely need are healing, shield of barbs, superior camouflage, careless lightening, and all the teleportation spells. The minor spells are cancel magic and dizzying wind. To get these spells first go to West Commons and at the druid ring buy teleport to North Karanas. Teleport there and buy the rest of your spells.
Now, if you have Kunark, go to the Lake of Ill Omen. The experience there is great. Try and get a group at the sarnak fortress but if you can't do that just get a partner and pull to the beach shore. You should level pretty quickly through these levels. (Note from Toymaker - You can get all the way through 29 in Ocean of Tears...after you get 24 go over to Sister Isle and hunt the Dwarves there till 27...then there are bigger dwarves till 29...you might have bad faction with Kaladim but who cares....)