Nothing screams noob like someone that cannot tell the difference between a Pale Ale and an Amber or someone that orders an IPA because all the cool kids are talking about it..."oooo, its a bit too fruity for what I am used to". There are quite a wide variety of different styles recognised according to the BJCP each with their own different characteristics and traits - yet beers are also not limited to this list. If you are going to be partaking in the bevies, at least have a bit of an idea what you are in for when you place your order. Similarly, if I see a new name on the menu and ask my friendly waitron what kind of beer it is "craft beer" does not suffice as a style...
I suppose this kind of ties in with the previous paragraph, but if you order an IPA it is going to be bitter as all hell and probably very fruity. Yes, the Weiss is going to have a nice banana and clove aroma to it and it will probably be hazy and fill you up in no time. Each style is different and this is the exciting part about beer. Don't send a beer back because "this is not what I ordered" - read "this is not what I wanted or expected".
Just because it comes from a small brewery in your local town does not automatically make it better than everything else and immune to criticism. Knowing how to spot a dodgy beer is equally important for two main reasons: it stops restaurants/pubs from selling old beer/beer through dirty pipes and it also stops breweries with questionable ethics and beer quality from reproducing (punning hard!). School yourself on what a good beer should taste like and what is appropriate for the style (again tying in with the first point). Also one should not feel bad to send something back if you detect some off flavour or aroma, but if so you need to be sure. Vote with your wallets people, support breweries and institutions that constantly produce/serve a solid product instead of just standing around consuming whatever is spewing forth from the taps.
Most small breweries have to bottle condition their beers in order to achieve carbonation and ageing and this can often leave some trub in the bottle (the homebrewers out there know what I am talking about!). For best results, it is best to pour your beer out into a glass of your choice leaving some of the sediment behind as best you can. There are of course those that like to mix it up and pour it all out, but I would rather sacrifice that last bit of beer.
All in all, that beer you have in your hand is brewed to be enjoyed. Brewed by someone with a passion for brewing. Someone that nine out of ten times has a day job that supports the brewery that you so flippantly dismiss. Give that pint a chance. See if you can find what the brewer was trying to achieve. What is he trying to say with his creation? Most times the most exciting beers are the most simple ones or the ones that challenge the conformity of a single style.
Beer is there to be enjoyed. To challenge what you know and snuck from your dad's drawer in the fridge in high school so go out there and enjoy what is on offer. Try something new every once in awhile and you never know, you might just find your new favorite beer where you least expected it. As a homebrewer, I think it is imperative to that you taste as many different styles as possible to give you a good idea of what you like and what you can do with your beer.
Grab some mates, order some random tasters and get educated while hanging out...what could be better!?