I want to dual boot Linux and Windows, but I'm not sure how I should do it. I currently have Windows installed to my SSD and was thinking of installing Ubuntu to it and partitioning one of my mechanical drive for windows. From what I have learned Linux is not friendly to the other partition if using the install disk to restore the OS, and this is the best compromise I can think of. I want to set it up so that if I do nothing it will default to Linux, and I would have to tell it to go to windows if I need Windows.
the drives - 120 SSD (current OS drive, windows 10) - 320 Mechanical drive x2
What I would is shrink one of the HDD's NTFS partitions (one with least amount of data) in Windows. And free up around 100gb and install Linux on the free space. If widows doesn't want to shrink it use gparted to to do it. Just back up data on the drive before you do.
What Taco_Bell said, During the install it should automatically pic Linux as the default. If you want to change that you'll have to edit the grub I suggest the Grub-Customizer but I'm still pretty new at this myself. As far as lack of friendliness towards the other partition. I don't think you can mount the windows partition while in linux but I'm probably wrong.
You can mount the windows partition as long as windows has been shut down correctly; however, windows can't access the linux filesystem. You can edit the fstab config file to auto mount the partition (Warning: you can really break your system if you do this incorrectly, but this is the best way to auto mount, also it's best to mount using the UUID instead of the drive path) . If you head over to just about any distro forum or linux distro wiki you will find everything that you need. I would probably use a spare HDD to practice before I make any permanent changes.
I've been dual booting Arch and Windows for a while now so I'll chip in my two cents.
You're probably going to want to install Ubuntu on the SSD, so I recommend shrinking the NTFS partition to leave ~10-20gigs for Ubuntu. I'm not sure how the transparent the install process is for Ubuntu, but really you should only set the / partition on the SSD and leave /home and other partitions you want on one of your mechanical drives.
Things get interesting now because of UEFI, which I'm assuming your computer is now using. Windows 8 by default will create 4 (I think) partitions, but there's only two you should care about, the EFI partition and the actual Windows partition. The Windows partition is the one you're going to want to resize for space. The EFI partition is essentially what the bootloader looks at to start the OS. The partition is useful because this can be shared with Ubuntu so that you don't need to create another partition and it made things a bit easier for me.
I had this setup with Arch and Windows 8 with the gummiboot bootloader. Gummiboot is a UEFI boot manager that has a nice feature where it will auto boot into the default OS unless you hold down a key. You can hold down space for a list, l for linux or w for windows. This sounds like the setup you want. It should be pretty straightforward to replace grub with gummiboot on Ubuntu.
The hardest part will probably setting up the ssd partitions correctly if you haven't before. Again, I"m not sure how transparent the Ubuntu installer is, if you can control the partitioning at all.
I also have a shared NTFS drive for my data I want shared between both OS. I ran into one weird issue where if I boot into linux after it was last shutdown by Windows, I could not mount the shared drive. However, if I restarted from Windows and then booted into linux, I could load it fine. I assume this happens because Windows stores some metadata on the drive to boot faster when you shutdown and this confuses linux when it tries to mount it. I didn't find it that big of an issue, but to each their own.
I have a 240GB SSD, 1TB HD and an external HD of 1TB.
I'm very new to linux but I learn fast so I want to switch my main system on linux.
Can I back up my Windows OS, wich is on the SSD, to move it to the HD, with my school stuff (like Eclipse and Visual Studio files) and all my other files and all my games, and acces to it after I install Linux for the first time ?
It would be wise to go ahead and make a small partition and try linux off of a flash drive first or until you find the/a distro that suits you. Otherwise (someone correct me if i'm wrong) go ahead and then migrate those partitions where ever you want them, pending you properly format the receiving disk prior or at the time of the transfer depending on what migration software your using.