So, if I currently have and SSD with 2 partitions C and D, one for Windows 7 itself and one where I install all my games and programs. If I want to install Linux Mint on it while keeping all my current files on it intact, should I create a new partition before installation? Or do I do it during installation process?
The installer is able to resize partitions, but it's best/safest to resize them using Windows. Once the existing partitions have been resized you can let Mint create its partitions in the free space.
I also have and HDD (drive E) which I use for storage: photos, documents... etc. Is there anything I have to do during installation to have it available from both Windows and Linux?
It should be detected & show up in the file manager automatically.
So I can just create a new partition, assign letter L to it or whatever, then during installation choose it as the one to install Linux on?
Partitions on Linux don't have the drive letters, but you still see the same partitions, is that right? So if I do nothing to my HDD drive, it will still be seen as a separate disk on Linux?
On Linux everything is represented on a single file system, e.g. on my system I have an SSD and 2 HDDs.
The SSD is where Mint is installed to and has been mounted as the filesystem root: /
The larger HDD has been mounted as: /mnt/hdd
The smaller HDD has been mounted as: /mnt/hdd2
I have manually set the mount points for the HDDs; any additional drives will usually be mounted under /media/<user>/ by default
There's more information about this in section 7 of my guide.
So, say I create say a 30GB partition for Linux Mint, which should be enough for the OS and swap. If I do that, would I be able to have my Linux games share the partition where my Windows games are installed? Basically I'll have
Windows OS (50GB)
Linux OS (30GB)
Installed Windows and Linux games (200+GB)
Will the above work? Or do I need to create a separate partition for Linux games?
You will need to use a partition formatted with a Linux filesystem for Linux software, as Windows' filesystems are more limited & don't store certain important information, such as executable flags.
Also just about any character is allowed for file/directory names on Linux except / and null (although individual pieces of software and scripts may not be able to handle more "exotic" characters).
Also, regarding desktop environments, what's the difference between Cinnamon and Mate? I'm looking for something that's similar to Windows XP or Windows 7 with Classic Shell. NOT Windows 10 nor anything that seems to be geared towards touchscreen/mobile devices.
I've read that Cinnamon is based on GNOME3, which is more "touchscreeny", while Mate is based on GNOME2, which was more classic? Is that correct? I've looked at a few screenshots, but it's difficult to tell the difference from them.
It's personal preference really... they're both similar. MATE is lighter than Cinnamon, but both are lighter than Windows. Cinnamon is a lot more customisable though IIRC.
I use Cinnamon with the "traditional" themes preset, which should be what you're after or close to it at least (you can tweak it further via System Settings --> Themes if not). This preset can selected via the Welcome Screen, under First Steps -> Desktop Layout.