This looks like a good guide:
http://techhamlet.com/2010/05/how-to-install-ubuntu-10-04/
I really hate this "Install Linux inside windows" business!!, how very stupid of an option is that! I'm guessing your playing with Ubuntu, because that is where I've seen that option! It's stupid because so so so much can go wrong.
As a Long term Linux user I would recommend only VM installation of Windows! [maybe you want to put linux in a VM in windows] You can plug a Hard Drive into the VM and try to Mount it in the Linux VM under windows (limiting hardware acceleration and native graphic drivers etc...), but your case may be different...? [... and yes your laptop can hack it] If you want to play games, your stuffed and you have to dual boot, wine is getting better for playing games on linux, but still sucks! (I say this because your coming over from windows and your just used to games running perfectly well on full FPS etc...)
If you go for an installation (dual boot), I would suggest - you need to understand 120GB for windows is an overkill, as is 120GB for Linux, and that, the 250 GB for data..... your not going to be able to use this under both operating systems, trouble is NTFS security descriptors, and NTFS is largely proprietary tech..., writing, reading etc... etc..., it's not a viable option, and no don't listen to anyone who says download NTFS drivers in Ubuntu and it works! their wrong and you risk loosing your data at some point!, it happened to me 5 years ago, maybe drivers are better now ... don't know, but I would still feel dirty writing to NTFS from linux... yuk!
You sound like a windows user, using linux
Partitions:
Code:
Size MountPoint Description
20GB / Ubuntu root partiton [OTT: but I dnt know ubuntu is somewhat bloated]
4GB swap Depends.... on your ram and what you want to do, rule is 1...2 times ram, but I have mine set to 2x cause I use memory intensive programs, you can always create a swap file later on /home and extend this, i.g I have 8GB fixed swap and I swap on 20GB when and if I need it to make 28GB swap space --- ridiculous I know by I use MATLAB, and MATLAB allocates memory contiguously !
100GB /home Your linux files
Make the above partitions ext4, excepts swap (its just type swap), it just works, not here to argue with anyone about XFS blah blah...
[This setup is ideal, Ubuntu is stupid for not advocating the above, because if '/' gets corrupted, then you can reinstall without harming your files in '/home'
120GB - NTFS Windows
this leaves 250GB you can do with what you want.
What do you want to use this for: if its music and video then that's fine for mounting in Linux and windows (read access only), make another 250GB NTFS partition. If you want somewhere to swap files between linux and windows (that means reading and writing) make a fat partition of 10GB (you will be restricted to file sizes of 2GB, can get away with compressing larger files, i.e. self extracting multiple file rar files, e.g. a 5GB file spread over 10 500 meg file)
or you can divide the 250GB between windows and linux.
The idea is usually to install Windows, and then install Ubuntu, because Grub (linux boot loader) is typically much much better to rescue etc..., and Ubuntu spoon feeds and detect your windows and makes you a grub entry...
If your really giddy about linux and competent then may I suggest playing with the big boys, i.e. Arch or Genoo
--- ok maybe not Ubuntu