Copyrights and licenses are not the most interesting subjects in software development. Unfortunately they cannot be bypassed, they have to be confronted. The free and open source software movement has always had a legal side which is working on this. The Software Freedom Law Center (SFLC) has released a guide called A Legal Issues Primer for Open Source and Free Software Projects (via Bruce Byfield). However, it might take some time to educate yourself through this 45-page monster. Meanwhile, know that by default every work gets copyrighted. If you want your work to be reused, just pick a license, any license.
