Waltz

what should I need to know about waltzes before I start writing one? Is there a specific form to it? anything about the key or something that specific?

Well, a Waltz isn't that misterious. You probably know already that it's a rather fast-moving dance, most usually in 3/4 (though there are examples of 5/4 and/or more complex meters). Quite often in ternary form. Very versatile form, easily adapts itself to almost any combination of instruments (Brahms and Chopin wrote them for piano solo, Tchaikovsky for strings or full orchestra, the Strausses almost always for full orchestra).

BTW, are you writing an orchestral, chamber or solo work?

It's a program symphony, kinda like your Adriana thing. A friend of mine wrote a comical story about a high school symphony orchestra, and it's basically in 5 movements, Intro, The Evil Ones, The Overdramatic Ones, The Romantic Ones, and epilogue. Basically, this is a bunch of little stories going on, and a bunch of conflicts (2 people get killed) but everyone finally settles for the final concert. So, this is for symphony orchestra, because the story is about a symphony orchestra, and the waltz is supposed to be for "The Romantic Ones" which is a combination of all the love stories (there's a cute gay relationship between the pic. and bassoon, 2 cellos love/hate each other, there's this big love triangle thing in the brass, and the trombone's a cat in heat), so...there.