First, I would strongly recommend you to set your Windows pagefile to a fixed size (min = max) and then reduce the size of Windows partition (C:) as much as you can (or about 10 GB larger that the present used space) using the Disk management Tool in Windows. Otherwise you may have problems with booting Windows via Grub bootloader which will be installed with Ubuntu.

Second, you can then boot your Ubuntu live CD/DVD/USB in "try without installing" mode and start GParted Partition Editor there to make partitions before Ubuntu installation (although this is performed at the beginning of the installation, I find it better doing this in advance). At his stage, considering that you can have maximun 4 Primary Partitions in a disk, you might need to create an Extended Partition in which you can have as many Logical Partitions as you might need. A Data partition to use jointly with Windows may be in NTFS format (with an appropriate entry in Ubuntu system file /etc/fstab), about 20GB Ubuntu partition and about 4GB swap partition, etc.