Backing your FOSS project with a non-profit organization is a great idea. Creating your own such organization, on the other hand, usually isn't unless you're a very large project (on par with LLVM, Apache, etc).
Instead, consider joining one of the several umbrella organizations that support FOSS projects (including managing donations and legal issues), such as Software Freedom Conservancy (which covers projects like Git, Mercurial, QEMU, Samba, Boost, Inkscape, and PyPy), or Software in the Public Interest (which covers Debian, PostgreSQL, ffmpeg, LibreOffice, MinGW, Arch, freedesktop.org, and others).
Instead, consider joining one of the several umbrella organizations that support FOSS projects (including managing donations and legal issues), such as Software Freedom Conservancy (which covers projects like Git, Mercurial, QEMU, Samba, Boost, Inkscape, and PyPy), or Software in the Public Interest (which covers Debian, PostgreSQL, ffmpeg, LibreOffice, MinGW, Arch, freedesktop.org, and others).