I'm new to the hobby (obsession?). I'm absolutely hooked, in spite of about 4 and a half gallons of really lousy oatmeal stout. My second batch is under my belt now, and looking back at my first I'm amazed at what I've learned since.
Didn't cool the wort (dumped it on top of 2 and a half gallons cold water in carboy, result being it didn't cool to 75 for about 5 hours)
Didn't aerate wort
Pitched dry yeast without re-hydrating
Fermented 5 gallons in a 5 gallon carboy without a blowoff setup (initially)
Had fermentation temps all over the place (I live in MI and heat with wood, gone during the day)
The result was an under attenuated beer (finished around 1.024) that tastes not much like an oatmeal stout. Some fruit/alcohol wine flavors.
Since then I've listened to about 40 hrs worth of podcasts (mostly brewstrong), finished one book (Papazians), halfway through J Palmers "How to Brew", bought "Brewing Classic Styles", started a brew logbook, purchased an additional 6.5 g carboy, ranco 2 stage controller, fermwrap, thermowell, yeast starter flask, and about 10 other things I'll remember after I post this.
My 2nd batch (dry hopped APA) is currently sitting at exactly 68 degrees awaiting bottling this weekend. High hopes for that one.
What a hobby.