Simple iPod Touch Backing Up / Update ios (4.1) Question(s). I'm in need of a

[Mgn]

bit help? Heyy, alright umm i wanted to update my iPod touch to the newest version which is the ios (4.1)
well at first it just told me to update my iTunes first..
which i did.
but as i was about to update my iPod touch it said "It Will Delete All Media" D:
well i wouldn't like that very much :/

Soo my question(s) is

How can i back up my ipod touch's media files (photos,music,videos,notes,contacts,apps,etc. )
to my computer(windows7) ?

How would i be able to restore it back on to my iPod touch?

(Step by Steps answers would be great! thanks)

OR

Is the iTunes Back up 100% sure that After the update, my stuff will safely be there to restore?

does it back up everything? (photos,music,videos,notes,contacts,apps,etc.)

i just want to be sure nothing gets lost or deleted...

Besides that,

The ios (4.1) update Question(s)

Is it really worth all the trouble?

What are some new features i can be looking forward to in the ios (4.1) ?

are there any kinda of bugs or crashes i should be aware of?



Thank you, for everything and helping me out.
Your answers are greatly appreciated. ~<3 :]
[Backing up my iPod Touch Questions are the ones i need more. The update questions are optional]