Re: Questions about installing/dual booting Ubuntu 12.10 on a second hard drive
Sometimes, I forget that what seems obvious to me isn't at all obvious, and certainly not to new users. Sorry for confusion.
The similarities between your needs and those of the linked thread are:
1. Any sort of partitioning is possible, and especially so if you actually want to put the new OS onto a disk of its own.
2. NTFS and ext4 can co-reside on one disk with no problems, the only drawback being complexity and potential confusion.
3. It follows that it is not necessary to move W7 to the new disk as you can easily add data partitions to the larger disk to look after any needed W7 expansion.
From the above, it further follows that:
Your plan is a good one. It bears many similarities to the linked thread because both seek to keep Windows where it is, create new ext4 partitions for Ubuntu, and already has/or plans to have a NTFS partition to be shared between the two OSes. In the case of the linked thread, it's all happening on one disk whereas you wish to spread it over two, but conceptually, it's the same desire with pretty much the same procedures in both cases.
So as not confuse you further, let me lay it out step by step (I'm lazy so will copy and paste many of my steps from the linked thread, with appropriate revisions):
1. Backup, then backup your backup. I am referring to your Win data here. It looks like you have W7 installed, so if you have W7 install/recovery disks, have them at hand. Backup always refers to some external media that can be ported to another box entirely if necessary, else it is useless and a waste of time. Either DVDs or an external USB device.
2. You don't need to resize partitions on your old HDD so the remarks concerning repartitioning don't apply.
3. Ubuntu has recently announced that future versions will only have 9 month support, so if you are intent on using 12.10, just be aware that you are committing to a journey on the unending upgrade treadmill. By contrast, 12.04 is LTS that will be supported until 2017. Choose your version wisely.
4. Your current partition architecture (on old first HDD) along with your proposed scheme (on new second HDD) is fine. Create NTFS partition, create ext partitions, and Ubuntu will go into the ext4 partitions.
5. You need a NTFS partition so ignore the corresponding comment #5. NTFS is still a horrible file structure, but you need this for Win, so you are stuck with it.
6. Create your Ubuntu partitions on your second HDD first using gparted, then map your various directories to these partitions during the install.
7. Create one partition of 30 GB at beginning of disk for /
8. Create one partition of whatever you want, but at end of disk for swap.
9. Create a third partition of, say, 400 GB for /home.
10 Create a final partition for data to be shared between W7 and Ubuntu. You will have to create this partition with Win tools because W7 refuses to play nice with other OSes. Format it as NTFS and this will be what you share between OSes. You will have to be careful to fill it only with data that you know both OSes can safely access: photos, music, common data files. You won't be able to use it for apps unless you dedicate it to only one OS or the other since any manipulation of app files by a foreign OS may render the app unlaunchable.
This above scheme will put you at the maximum number of partitions for your second HDD if you use the old MBR partitioning scheme. If you use GPT, you can have up to 128 partitions.
When installing Ubuntu, make sure that you choose "something else" when the install process asks you early on where you want to put your install. First, make sure that you change to drive sdb (this is critical. You do not want to overwrite your W7 drive "sda". This is also the reason for backups, in case you screw up at this point), then map / to the partition you defined in step 7, swap to the partition you defined in step 8, /home to the partition you defined in step 9, and leave the partition defined in step 10 alone for now.
Finally, make sure that GRUB is installed in sda (your W7 drive). GRUB will overwrite your windows bootloader, but this is what you want. Henceforth, GRUB will handle the loading of your operating systems and will offer you the choice between W7 and Ubuntu.
Write down the whole process to make sure you are comfortable with it. Before proceeding, ask questions if any occur to you. Remember, you are actually in a better place than someone trying to make two OSes cohabit on one HDD.
Re: Ubuntu 12.10 or 12.04
It goes without saying that the newer version will offer more bells and whistles whereas the LTS will offer better stability. You must use your own initiative to discover what new bells and whistles the new version offers and whether these are important enough for you to get on the upgrade treadmill. I consider myself a seasoned Ubuntu user and I prefer the stability of LTS to the wow-appeal of new stuff. Only you can determine what your needs are, so there is little that anyone can do to advise you here.
Newb: How far must I jump to clear the ledge halfway down?
Guru: It's bad to jump off cliffs. Let's look at better options.
Newb: Stop harping about "best practices" and just tell me.