OpenOffice is decent. It's like Office 2000 or 2003. You can also use Google Docs, though it's kind of weak.
I don't like GIMP, but if it has to be free that may work. If you do enough photo editing, maybe consider something like Adobe Lightroom.
No idea on the backup software. Windows 7 has its own, so maybe see how that works for you.
Here's some other free shit you should download. All this stuff I personally use, even though I have access to commercial variants that I used to think were better:
- Security software: Microsoft Security Essentials
Free from Microsoft with Windows 7. Very highly rated anti-virus suite as well as firewall protection and other stuff. Good performance too.
- Music player: Foobar2000
Quite frankly the best computer music player. A dealmaking program to convince me to not switch from Windows. Use something like iTunes only to copy files to your device, or download music, but Foobar2000 is the player for those who want the highest quality playback, the most control, the ability to play virtually any music file, and all that. It's not for everyone, but for those who like that level of music player power, this is it.
- Photo/Image viewing, cropping, conversion: Irfanview
I used to like ACDSee, but it got super bloated and annoying.
- Archive Extraction/Creation: 7Zip
I still use, and even bought, WinRAR, but 7Zip does it all and has great multiprocessor support.
- PDF Viewer: Foxit Viewer
Adobe Acrobat Reader is so clunky and bloated compared to Foxit. What I REALLY hated in Reader was that it wouldn't let me force settings like viewing documents in continuous mode rather than whatever the PDF creator thought people should view it as. Also Foxit lets me run multiple instances of the program for separate documents, which Reader did not let me in the past. Hell forbid someone want to read two documents on the screen at the same time. They're also very open to having bugs reported in their forums.
- Mail reader: Mozilla Thunderbird
I personally use version 2.x (because the column sorting fits what I like) but supposedly the newer ones are decent too.
- System tasks: Process Explorer
Better than Task Manager! It also has some nice CPU/RAM, etc. usage graphs that the other doesn't.
- Photo stitching: Microsoft Image Composite Editor (ICE)
Turn your 6MP camera into a 100MP camera with advanced stitching. It's EXCELLENT stuff, fast and quality, and is the software behind creating environments in PhotoSynth (BM 2008 temple
- Virtual Machines: VMware player
Now you can run an OS inside your current OS. Like Windows XP while running Windows 7. Or Linux on Windows 7. I use it all the time. The new version of VMware player now allows you to create virtual machines (VM), instead of just running them; so now you can run whatever you want without any commercial software.
- Encrypted drive software: Truecrypt
Traveling with some sensitive documents that you wouldn't want lost or stolen? Keep them on an encrypted drive. Works great with a VM (see above) run from that drive. Keep it on a flash drive so that you can take it with you.