Both OS-es are good. There are some diferences bettwen FreeBSD and Linux:
- FreeBsd has excelent handbook (FreeBSD Handbook) that is very good for offline info. Linux on the other hand has some docs but not as freebsd handbook
- FreeBSD is somewhat harder to set up in some cases. If you use DesktopBSD or other "nice and good gui" freebsd derivate then you will have no problems.
- for bsd there are ports. You can use any bsd derivate and still you can use the same ports. For linux you can compile from source (it´s universall for all distros). For binary packages you are lucky if you use ubuntu or fedora/opensuse because these are mainstream distros and for them there are too many packages ;)

I use linux but i would like one linux handbook just like the one from freebsd ;)