help, installed VMware fusion and some software is telling me to partition larger

Help! I have a Mac mini that I installed VMware Fusion 3.0 and Windows 7 so I could load a graphics program called Creative Memories. There are several programs I need to load. I loaded the vm ware and windows program, with no problems. Then I loaded the Creative Memories Memory Manager 3.0. This loaded, but when I went to load the Story Book Creator, it told me I did not have enough disk space. I see that I have 30 GB of space for this VMware fusion, and I have tons of space left over after I loaded 3 of the four programs above(27 of the 30 gb is available). I still have another couple of programs to load, of which are, Story Book Creator plus 3.0, disk 1 and 2 (needs 2 gb ram and 2 gb hard drive).

My question is, can I partition a larger chunk of hard drive space to VMware so I can access these programs WITHOUT ruining my previously loaded files/programs that I already have on my mac mini? Secondly, How much space should I designate, and will I have to reload my windows 7 and other programs on this virtual machine? And thirdly, if I ever install Microsoft office on this virtual machine, how much space will that take up, if I only have 30 GB partitioned?