That is a really hard question to answer, actually, there can be four primary partitions. One of them can be an extended partition, which can contain any number of logical partitions. Therefore, it all depends on your personal need.

First you can make an system partition, 30GB is enough for windows 7, a little more for Windows 8, take 50Gb is quite enough. Then make another partition for your personal data: documents, musics or movies, if you think that’s not convenient to manage files or folders, you can create more partitions for special use.

It’s ease to create partitions for Partition Assistant, you don’t have to remember all the codes or phrases to do the partition job. You just run it, make few clicks and it’s done.
Run PA, chick the bigger partition, Create partition on the left, adjust the amount, OK then Apply. Or you just press Enter to quickly create partitions. See, that’s the whole operations.
Have a try.