The choice of 2, 3, or more partitions is highly personal. I typically do 3 partitions (swap, /, /home), however starting with just 2 partitions (swap, /) is perfectly fine and normal. In fact, often times when starting with linux it's easier to reinstall the system 100% than it is to try to fix system issues or manage a separate /home partition. But really, it just comes down to personal choice. I would recommend 2 partitions for VL (swap and /). Just so you know, if other partitions are not specified (i.e. /home) then they simply fall within the root partition (/).
Swap size is also very personal. I've found that I've never had need for a swap partition greater than 512mb on an older laptop (amd 1500+ with 512mb ram), however if you plan on audio/video processing or heavy photo processing then a larger swap would be preferential.
To sum up, my recommendation would be:
Windows 2000, NTFS, 20GB
VectorLinux, ext3/reiserfs/xfs, 19.5GB