Tagging on to LockeColeMA's advice (all of which I second), shopping at the Auction House will be expensive if this is your first character. Take 2 gathering professions (skinning and either herbalism or mining), and take up fishing if you have time (an excellent source of income at mid-levels). Sell all your skins, herbs, ores, etc. at the auction house. As a druid you can put off first aid for a while, since you won't have much downtime anyway if you're leveling feral, and sell all your cloth as well. Some white items you get off mobs, like spider's silk, sell for a surprising amount at auction as well, so check those sorts of things for the going rate on your server - auction anything you can make more then vendor prices for.
All this stuff will net you plenty of money for your first mount at 40 and buying eq as you go. My advice, though, don't get too crazy with it. You really don't need to upgrade your gear all that often while leveling up, maybe every 7-10 levels.