is there any way that i can put an external hard drive on my wirless network?
i want to store a whole lot of music on it and be able to roam around my house with my laptop and access it...
If you have a desktop/other computer with all your music on it, you should be able to network the two together, so you can access all the music from your other computer.
Check out the Mac Rumors Networking guide
There are network-accessible hard drives as well as routers which will accept hard drives and put them on the network, but as far as I know there is no cheap solution to that problem.