I play casually. Got a comfortable chair, a tv behind the computer and a very nice, large cup for whisky cokes.
Pretty much any class can run through the game up into the late 80s very casually. Just pop a merc and go! Regardless of class use a tank merc till 60, then depending on the class you choose to play swap out to a different merc. As your likely looking to have fun leveling, I would stay awa from the typical leveling path (cresant reach>blightfire>burning woods>acrylia caverns>etc) and maybe go dungeon crawling with a merc. You will see and experice a lot more adventure that way. You can use this chart to see what area you can go at which level: http://everquest.allakhazam.com/db/zlvlchart.html Enjoy!
Since I've returned this time I've only hit up older zones, purposely trying out zones I've never been to before. It is a blast, although lonely solo, but I don't think I really intend go past a certain level. Just kinda piddling around in the lower game. Honestly xp at lower levels is going to fast for me I'm sure I won't be able to level everywhere that I would like.