Like my esteemed fellows above said, there is one main thing you should do to become good at pencil art, and that is practice, practice, practice. Some will tell you you should begin by drawing cubes and globes and the like, and then slowly evolve, but I think it's better to start off by doing what you like doing, you can always go back and brush up on the basics later. Starting with things you like will help you develop a love for your craft, and of all the things you need to become good, love for your craft is the only one you absolutely, crucially need.
Don't get too discouraged when you can't do the things you want to do right away. It will take time, but if you persist, and keep enjoying what you do, you
will become a good artist, and this is important:
DO NOT LET ANYONE TELL YOU YOU'RE NOT CUT OUT FOR ART. Don't believe the myth that artistic ability is something you have to be 'born with'. You'll notice that the people spreading that shameful lie are always the people who couldn't draw a decent piece to save their lives. I keep hearing this tripe, no matter what kind of art it's about. "You need to be born with it". Don't believe that, it's utter and complete rubbish, used by quitters to justify their giving-up, and often wielded out of jealousy against someone who's practicing and becoming good at something they wish they'd pursued. The
only thing you need to be born with is a love for art and the desire to make it - anything else can be learned.
A good artist knows better: talent is nothing else than a small head start, but practice and skill are what make you a good artist, and if you keep at it, and keep loving what you do (though you may hate it at times), you will be good at it some day. It won't always feel that way - you'll see beautiful pieces of art and think you'll never be able to make something that good, but the truth is, YES YOU WILL IF YOU KEEP AT IT.
I personally feel that you shouldn't start by going to art classes. Art classes can do a lot for you, but only once you've mastered the basics, have an idea of what you can/want to do, and know what you need help in. If you start attending classes without the basics, you'll be lost and get discouraged. Build some skill yourself first so you have some baggage to bring. If you feel yourself hitting a ceiling, that's when you should start going to classes. I never attended a single art class and my drawings are... well, not bad I suppose.
As for pencils, well, I know ms. trixyblue above uses a wide array of pencils, and many artists will doubtless do the same, but if you're unsure of how to choose your pencils, start with sticking to a normal 2B one. Anything below that is too hard, and is suited for technical drawing (or possibly very light sketching), but not for art. Definitely stay away from anything that has a H on it. If you find yourself needing more darks, pick up a 4B or a 6B or even an 8B, but personally, I only use a single 2B pencil, and I can shade as darkly as I want to, so different pencils may not even be necessary to you.
Landscapes aren't my strong point, so I probably won't be able to help much with those, but nu_clear_day's advice (and all the advice in this thread so far really) is solid. Keep your pencil moving. If you get stuck somewhere, don't get frustrated, just move your pencil somewhere else and draw there, and return to the other part when your mood's changed. If you're really stuck, stop and take a break. Leaving a drawing overnight can make you look at it in a completely different way and give you new insights so you can continue work with fresh energy.
Oh, and one more thing, you want to learn how not to svck, well I'm sorry. Paradoxically, if you're a good artist, you will forever svck. If you're not sure what I mean, let me explain: it's only beginners who think they know it all. The serious artist knows there is always room to improve, and if you're a good artist, you'll keep seeing things in your own work that need improving. That's what drives an artist to become better at his craft. So be proud of what you do, but know you will never, ever be perfect.
Should you have some works you'd like to show and get some pointers on, I heartily welcome you to the http://www.gamesas.com/topic/1204425-esf-artistry-thread/page__fromsearch__1 where we have some damn impressive artists who'll be happy to help you get better!
