As I go on homebrewtalk.com or BeerAdvocate's Homebrewing forum or anywhere really that has people posting about brewing, I tend to see the same problems and questions being posted over and over. It's gotten to the point where I don't even respond because I'm fed up answering the identical question for the 50th time. People need to realize that their problem isn't unique and it has been asked multiple times before and a quick google search will find them their answer. I'm going to post the questions and my answers here so in the future I can just copy and past these responses (because I know nobody is reading this).
"My airlock isn't bubbling/I don't see krausen/am I done fermenting"
Airlock activity isn't an indicator of fermentation aka bubbles don't directly correlate to fermentation efficiency. Due to head space, faulty seals, etc, you might not see any airlock bubbles for the entire fermentation and have a perfectly attenuated beer. Also, just because you don't have a huge krausen doesn't mean your beer isn't fermenting. Sometimes the krausen is quick to fall and you miss it or the yeast strain itself doesn't produce a huge krausen. The only way to determine fermentation is to take a gravity reading. I repeat, the best way to determine fermentation is via a gravity reading.
"Should I make a starter/dry yeast vs liquid yeast"
First off, I don't use dry yeast and I understand it is cheaper and you can still make good beer with it. If you're going to use dry yeast, make sure you rehydrate it with 1 cup of sanitized (read: boiled and cooled) water at 95-105F. Any hotter and you'll kill the yeast, cooler and it's not properly rehydrating.
Now, if you use liquid yeast, most vials/smack packs say they're designed to include enough yeast cells to ferment a 5 gallon batch of beer, and while this is certainly true (you'll make beer), you may need to make a starter to make the 'best' beer possible. Yeast is fickle and I won't get into all of the specifics, but to produce the optimal beer product yeast needs the correct fermentation temperature, pitching rate, dissolved oxygen content and many other factors which affect the finished product. A starter's main goal is to activate the yeast and build up cells to an appropriate pitch count. There are a few yeast starter calculators out there but Mr Malty is probably the best and will give you an accurate way to estimate cell counts.
"Critique my recipe"
This is a common post and one I actually don't mind answering because it is a somewhat unique question. The problem with this post is most people post incomplete information. The number one thing that needs to be posted in a recipe critique question is "what do YOU want the beer to taste like". What hop flavor do you want, if any? Malt back bone? Do you want it to finish dry/sweet? ABV? A good example would be "I'm looking for an IPA with a bright, citrusy hop flavor, a little malt backbone, and I want it finish nice and dry and about 6% ABV". This is something people who are going to help you with need in order to give you good advice.
Also needed to be included:
Recipe (grains with amount, hops with amount and time used, anything else going into boil/mash)
Mash Temp and length
More to come in other parts but remember RDWHAHB