I'm new to Ubuntu/Linux and I'm thus not very used to working on it. I used to have a Windows 7 and currently I dual-boot. I'd like to change to only Ubuntu. But I don't want to lose any information. I have a lot of songs, movies, pics, etc. saved on my computer but I have no idea how to get it from my Ubuntu desktop. And will all this information be lost if I change to Ubuntu? (I have a LOT of stuff so using a hard disk, USB is not an option.)
One thing you should be able to do is go under
Places -> Name of your Drive -> Opposite Click -> Mount
and if it does mount you will then be able to access it, see what's on it just like you would be able to do in Windows. If that can happen then it's a simple matter of drag and drop.
If you cannot see it in your Ubuntu partition then you can use an external USB HD like a Western Digital backup drive or something like that and just copy all your files/folders to that external drive, then plug it in your Ubuntu partition and drag and drop it to that...other than that there really isn't any easy way of doing it...
it isn't clearly stated on which setup-variant you run your systems, but maybe you meant the following:
If you have had your 'Ubuntu' installed via the 'WUBI'-Installer, so set it up as a virtual partition, which is stored as one or more files inside the 'Windows'-Partition, then you can access the 'Windows'-contents through the 'host'-folder.
In Nautilus you find it in the tree view under 'File System', or by clicking the hard-disk-icon in the breadcrumb-selector topping the file-view where your files and folder-contents are shown (the main visual of nautilus).
As an alternative you can open up a terminal or use the keys [ALT]+[F2] to open up the run-command and there typing in > nautilus /
The slash represents the root of the 'File System' and therefore is the topmost point in all of your folder-tree-structure.
If it is not the case that you just can't see your 'Windows'-partition, because it is inside the 'host' to hinder you deleting files necessary for running Ubuntu, then you might want to check if, due to a update- or setup-failure the system doesn't perform ntfs-access.
To find out if your system supports windows-partition-reading you can start Synaptic or the Ubuntu Software Center and use the search field (positioned neat to the main menu) to look for 'ntfsprogs' or for 'libntfs' and make sure one of them is installed.
There are several more ways to perform all these tasks, so just take it as a hint.