Installing Ubuntu on a laptop that has Windows 7 and Linux Mint

[taodoe9.amabel at recursor.net]

We currently have a laptop with Windows 7 and Linux Mint 11. We plan
on installing Ubuntu 11.10 and Linux Mint 12. What is the best way of
installing these two linux distros? I'm particularly uncertain of the
best way to answer the partition questions that the installation will
ask.

I booted up the "Ubuntu 11 Iso" on my computer. The installer was
aware that I had "other operating systems". It asked me whether I
wanted to install Ubuntu 11.10 alongside them. I did, and then I was
led to "Guided Installation". I saw this screen:
http://i.imgur.com/pOanH.jpg

But that worried me. Where were was Linux Mint? And why was Ubuntu
going to be installed in sda3? sda3 is Windows Recovery Environment
loader (ntfs), according to the "Manual Partition" option. The screen
does say that "4 smaller partitions are hidden", but that scared me.
So I went and clicked onto Manual Partitioning.

See http://i.imgur.com/lBFsb.jpg

sda1 ntfs 1.6GB Windows 7
sda2 ntfs 209GB Windows 7
sda5 ext4 93.9GB Linux Mint 11 Katya
sda6 swap (linux-swap) 4.1GB
sda3 ntfs 11.1GB Windows Recovery Environment

Some questions:
1. Why is Windows 7 split into sda1 and sda2?
2. Do I need sda6 linux-swap?
3. What's the proper way to make room for Ubuntu? What must I click on
the screen?

Also, I'd like the 2 distros to share the same "home" folder. By this,
I mean that I want both of them to point to the same place for where I
save my stuff (same Downloads folder, same Photos folder, same
"Recent" stuff, etc)

The laptop has only one hard drive.

Any other advice will be appreciated.