Personally I'd never be able to constrain my OS to use just 32GB of space, be it Linux or Windows.
What you can do if you know you're not going to install a huge amount of programs to your Linux OS is create a separate partition for your /home directory.
That's like the C:\Users directory in Windows.
When you're installing Ubuntu you just go to the advanced partitioning option during install, where you specify your SSD to use an EXT4 partition for most of the drive, leaving 1-2GB or so to create your "swap" partition, which is like the pagefile in windows, except obviously it's a partition not a file.
Then you allocate another EXT4 partition on your 500GB drive, and that one will be for your home directory.
You can set up the partitions using gparted or some other partitioning tool beforehand if you like, but when you're doing your Ubuntu install, you need to go to the advanced setup option where you set the partitions, so that you can allocate the mount points.
So you set the EXT4 SSD to use: "/" as its' mount point, which means it will be the root directory.
Then you set the EXT4 partition on your 500GB drive as the "/home" mount point. Which will tell the Ubuntu installer to use that partition for your equivalent of C:\Users.
Neat huh :0)
Only problem for me is that I think I'd probably even install more than 32GB of programs on the root fs. As even though I'd be installing all my windows games in wine, which stores it's files in the home directory, I found particularly when getting used to Linux, I became a package manager fiend... Once you open the Ubuntu software centre and there's millions of free apps which you're not already familiar with, it's awfully tempting to just go through and install piles of programs just to get familiar with them cause there FREEEEE! :OP
As for windows, I know that you can move the MyDocuments and MyVideos folders etc to a separate partition, but generally Windows is a space hog anyway so I'd definitely want to leave at least half of your 500GB drive for Windows.
Bearing in mind that you can mount your NTFS partitions inside Linux and read and write files, (without the ability to set file permissions).
While on Windows, you won't be able to easily mount your EXT4 partitions. There are programs I use like this one:
http://sourceforge.net/projects/ext2read/
Which will allow you to read your EXT4 partitions in Windows, but with that particular one you have to copy the files to the NTFS partition before you can open them.
Where as http://www.ext2fsd.com/
I think would allow you to mount your EXT4 partitions in Windows, but I found it tricky to set up and potentially a risk of damaging your data.
Having said all of which, if you're editing digital media I think it would be nice to have a 32GB SSD to use for working with your large image and video files, if you're going to be doing things that require a lot of read/write of the data. For example if you want to edit segments of video and save multiple copies while you're working with them. Though if you're working with video, 32GB would be a bit confining. I'd go for a larger SSD.
Whatever you decide to do, you can always copy your Linux partitions to another disk in the future if you choose to, and they'll boot just fine. You just need to boot up something like:
http://sourceforge.net/p/boot-repair-cd/home/Home/
or http://www.supergrubdisk.org/rescatux/
Which will let you update your grub2 boot loader configuration so that they point to the new hard drive.
You can also do that with windows by changing your BCD, http://pcsupport.about.com/od/fixtheproblem/ht/rebuild-bcd-store-windows.htm
