The first beer I ever made...was also the first beer I ever made. A terrible first batch of beer can be pretty discouraging, and I almost didn't give it a second try. Thankfully, by the time of my second batch, I had just moved mere miles from Northern Brewer. Had it not been for living near a quality, local, home brew store, I may not have gotten back on the horse.
Here's what not to do:
Failure #1 I made beer from a pre-hopped, canned kit. You can make drinkable (but not great) beer with these cans, but the dry yeast that comes with the can is a liability. I used the dry yeast from the can.
Failure #2 I fermented with my crappy yeast on the porch. Granted, it was fall, but ambient temperatures are rarely good to yeast without some level of control. Also: sunlight.
Failure #3 I sanitized everything with bleach. Bleach can be an effective sanitizer, but it needs to be mixed in the right proportions and then rinsed thoroughly. You also still need to be fastidious about sanitation, especially when re-using bottles. I was not.
Failure #4 I didn't use the right tools for the job. I fermented in a 5 gallon (not 6.5 gallon) bucket that housed barbecue sauce for the first 6 months of it's life. I drilled a hole in the bottom of it, installed a spigot, and used it as a primary from which I bottled directly. I also attempted to boil my beer in a small kettle that was filled near to the brim. After several boil overs, I ended up splitting the wort among 4 different pots and pans of various sizes on the stove in between running around and trying to clean up wort from on and around the stove.
In short, it was a disaster. The beer ended up infected, overcarbonated, and underattenuated and didn't taste much of beer. In retrospect, none of those things are very surprising but I did learn a valuable lesson: don't screw up and skimp on every single part of the brewing process. By the next go around, I purchased some no rinse sanitizer, a properly sized kettle and a real starter kit, and life was much better.