Hey all! I am new to this forum and also new to apple. I made the switch from pc to mac about a month ago and am enjoying the learning process. So far, no regrets! Now onto my need for help.

I am in the process of designing my home network and want to be able to do specific things and need specific help on making this happen for me and my family. I have searched the internet over and have not been able to find the help I need and hope that I can here. I will explain each below in no specific order our "wants" and any advice/guidance you can give me will be greatly appreciated! I will also list what equipment we have currently that we can use before buying additional equipment. Thanks in advance!

Current Equipment
Me- 13" MBP i7
Wife- HP Laptop
Apple TV connected to den tv
iPad 2
HP Media Center PC (Possible Media Server?)
1TB Seagate Goflex Home Backup drive
(2) iPod Nanos
iPod Touch
Linksys Wireless N Router

1)ITunes - I would like to have one Itunes library that my wife and I can share on different computers. Currently we have my apple id that we use to buy apps/music/movies and then me, my wife and son load our iPods/iPad. Is there a way for my wife to have access on her computer as well? Should we have multiple apple ids? I was told by a friend to have one apple id that way you only have to buy media one time and share across multiple devices. It would also be nice to store on network drive to free up space on our laptops but would still want access remotely. Would also like to play music through out the house on wireless speakers (do not currently own)

2) Media Server - I am wanting to store all of our videos/movies/photos/music in one location at my house that I can watch on our den tv as I am in the process of ripping our dvd collection. I would also like to have access from any pc/ipad in the house as well as remote access to these files as well, such as watching movies while traveling. Not even sure where to begin with this. Just have movies I have ripped currently on old external drive.

3) Backup - I am wanting local backup as well as an offsite backup for my mbp, for my wifes pc as well as all the media files.

If you need more specifics, just ask. Thanks again for reading this and again, all help is appreciated!