For learning Wordpress, I found it best to grab a few templates (lots of free ones out there) and see how they work. Very quickly you see the basic tricks.
For plug-ins, go to the standard plugin site and go through all of the "popular plugins." There's a zillion, but you'll probably have 10-15 installed before you're done, so it's worth pawing through them. Maybe decide to add one a day.
There's also the curated plugins that WPEngine has. (Fair warning: I'm a co-founder.)
For more specific reference, these are the plugins I use (yes, actually USE) on my blog :
Final caveat -- You'll notice these on my blog, plus things like the "Tweet this" magic button. Most of these I've un-hooked from their standard installation and re-hooked using my own custom PHP, so that's why some of it will act/look differently on your site.
That's just the cost of getting things JUST the way you want. But out of the box all these plug-ins are good.
One of the better places to learn WordPress by asking questions is the recently launched WordPress Answers by StackExchange (from the same company that runs this forum.) If you have a WordPress question chances are excellent you can get it answered WordPress Answers just like you can get startup questions answered here.