For the reading part that person meant emotional books, when you order them online select the smiling face icon for that category of books.
For the emotion books they only take 30 or so minutes in game time to receive a buff. So you would want to be careful what order you stack your buffs. The emotion books don't have a time to finish reading from what I saw, there was no filling in circle to estimate time til finished. And you can use them multiple times, I won't say infinitely yet but I have used the same book four to six times now.
I am also curious if there are buffs lasting longer than four hours, that seems to be the standard time for most of the positive buffs I receive. Only buffs I get for a day is negative ones, like from being eaten by my Cowplant so that I can milk it or scrape it for a microscope.
The second to last item in the Kitchen Appliances is a Tea Makerasa. The item is 275 Simoleons so cheap for the effect it gives, and each brew gives three cups for 15 simoleons each. And each pot of tea lasts 10 hours from the very beginning while it brews, so around 9 and a half when you begin drinking. You can lengthen that time by pouring all the tea into individual cups and stop the auto-drinking process and throwing them into the fridge, gives you a nine day window to decide when to drink it.
Oh right the tea buff is four hours like most other buffs gathered from food and items. Not sure why I wrote three.
I know focus helps with chess and programming. Inspiration helps with creative skills such as painting and music. Confidence of course helps charisma.
I would say try a lot of different things. Maybe back up your saves so you can revert to an earlier partd since you will be neglecting other things. Or make a new set of sims to test all these items out. As the game just came out I am not an authority on this, just wanted to share some of my observations.