For me it was a process
took about three years to change from 98% Windows (7) and 2% Linux to 100% FreeBSD.
If you start with FreeBSD, and being completely new to the world of un1x,
I recommend to have a second, additional machine (old hardware) you can experiment with, having no data of any worth on it, and another one running, reading the handbook, manpages, how-tos, tipps, tricks, and problem solutions, as this forums are a goldmine for those.
Getting into FreeBSD to me is mostly two things:
1. Learn to work with the shell.
Most use bash or sh. I prefer tcsh, and sh for scripting.
But this depends highly on personal taste, or what you want to do.
The nicest thing about FreeBSD is you don't need to stick with anything "but everybody else do it this way."
If you don't like bash (which I can comprehend), but are very comfortable with zsh, well then use zsh.
With FreeBSD you can, you're free.
(Except: Don't try to change root's login shell! That's a dangerous trap.)
2. Learn to read manpages.
The official handbook is of course the main documentation, and it gets you pretty far,
but no book can cover everything.
But the manpages do.
They are a gold mine.
Especially the lower parts refer to related manpages, and files.
Additionally take a peek at your /usr/local/share/doc/ - another goldmine.
(I have it bookmarked in my browser.)
And get additonally books on FreeBSD like "Absolute FreeBSD",
or others, if you want to dig into something specific deeper.
Participating this forums for several years
I estimate over 90% of all questions could have been answered by oneself by just reading the handbook, or manpages. Nearly all of those questions a beginner may have, are already answered anywhere at least once, mostly within this forums.
Learn FreeBSD, experiment with it, try things out, do some tests, crash disks, reinstall, play with it.
Until you feel confident enough to set up your production system.
Of course you don't have to become the total geek for that.
FreeBSD is pretty tolerant and robust.
Rule #1 in FreeBSD:
Don't panic!
When anything bad happens, stay cool!
There always is a solution.
You may experience at the beginning many occasions when the machine will not start completely anymore.
That's quite normal. I think we all experienced that.
Most of the times it's just because you tinkered something within /boot/loader.conf or /etc/rc.conf.
Just type what the system message tells you to get a proper shell running,
mount your partition writable (it's all in the handbook),
comment the line which caused the trouble, and reboot.
Anyway in almost all cases there is a solution, and at least you may get to your data.
Last straw would be ask in this forums.
I am regulary surprised what gurus may post here tricky solutions I never thought of in my wildest dreams.
If you got this you're in.
Step by step I moved more production to FreeBSD,
until I plugged off my Windows 7 Pro HDD.
Two years later also Windows 7 Home (Games) went into the cupboard.
Since last year I have a completely new machine which has never seen anything but FreeBSD (Windows for games within VirtualBox, okay)
I miss nothing, have everything I need, and get better every day at FreeBSD.
Just simply read.
Don't rely on video turtorials - way too inefficient.
read.
Anything else will come automatically.
In the retroperspective FreeBSD is really simple:
Install from USB-stick-image,
get a x-server running, which is not the "black magic" anymore like in the 1990s, when we had to fumble with mode tables on flickering screens, just don't expect the latest graphics adapter released yesterday will work.
Get one from last year, even costs less.
Decide for a DE or WM - you may change this anytime.
The rest is pkg install, freebsd-update, and reading the handbook, and manpages,
and enjoying a powerful, reliable, robust, and stable system,
you may have full control over,
which doesn't piss you off every couple of months.
Ah, yeah, one last crucial point:
Don't try to adapt FreeBSD to you experiences with any non-BSD system,
this will miss the whole point completely.
Adapt yourself to BSD.
Don't think Windows,
think unix.