The e46 bumper wont directly fit...Meaning you can go out and pull one off of an e46 m3 and slap it on your car...But they do have many companies that make bumpers that look like an e46 bumper that fit on e36's.
Check out ebay and a company called MA-shaw, they make carbon fiber wide body kits, normal body kits, etc.
For BMW help check out www.bimmerforums.com
. There is also a new site I just joined with very small amount of members that are very knowledgable. www.bimmerportal.com
. Plenty of DIY's on that site as well.