You can get the owner's manual off of the BMW Owner's Circle website: https://oc.bmwusa.com/CFALogin/Login.aspx
. But that manual does nto tell you how to fix anything. It is just the factory manual that comes with the car.
What you need is the Bentley BMW 3 Series (E46) Service Manual (ISBN 0837612772). You can get it from several different places online. This is not free, but it will save you a lot of money in the end. I haven't seen any PDF downloads for this manual on the web.
The good thing is that for most of the projects you may have to complete for your car, you can find DIY step by step instructions online, or you can just inquire here on the boards -- alll for free