It may be irritating at first, but prioritizing the Hermit Arcana's sidequests (aka "the fox") when you're deciding Social Link time is generally a good time investment. The reason for this is that the fox eventually travels with you into the TV dungeons, allowing you to spend your cash to get a full HP/SP restore across your entire part. The higher your Social Link with him, the better the discount. This will quickly allow you to clear story dungeons in one day, freeing up days to let you focus on your other social links.
Honestly, the version of P4 I played through was the original, and it had an amazing strategy guide that is totally irrelevant now for Golden. It played out like a TV guide, making recommendations on what you could do to best use your time, but overall just giving you a layout of who was available on what days so you could best plan out your time without actually spoiling you on the plot.
Also in regards to social links, don't neglect your school social links. They're only available when school is in session, which is a problem when you have long periods where school is out of session like the Summer.