Hey All. I'm a beginner to violin and I am in the process of getting a teacher. I played guitar for 8 years and taught myself and although I would consider myself decent, I know that if I took regular lessons I would be way ahead of where I am now. So I am definately going to take this instrument seriously and take weekly lessons from a professional violinist(she is a friend of the family). Anyway I have some wuestions before I start my lessons. How do I know what postion to play a song in? Lets say I have a piece of music and it requires me to play a d note. Logic would tell me that its the open note on the d string but am I wrong in this thinking? How do I know which note on the fingerboard is the right note for the piece. I never learned how to read notation for guitar. I always went by tab and numbers

Maybe you should get a book orsomething on positions and reading music or something. I know that there are even some computer programs but the name of the program has slipped my mind. Sry!

In case you can't get the book/program, You could always teach yourself.
Ok...so you have the staff and the note that is below the 5 lines is D. That D is the open D. Then you could just count up/down from there until you learn better. Hope I was at least a little help!

i would not worry about it till you have your lessons... your teacher will help you... just know the names of the open strings and where they are on the stave...

To learn reading the cleff quickly, you might want to either get your first lesson books this way

or write out your music with large note heads and write the note name inside it, or just write the note name above or below it. You will learn everything pretty fast regardless

If I'm understanding your question correctly, some notes and passages are more obvious than others when it comes to proper position. There are a lot of different factors to consider when choosing a position. Normally, when there's a fast passage that you try to play in 1st position and you have to switch strings to do that, you would want to switch to a position where you did the least possible amount of string switching.
You mention playing an open D as obvious, but what if it's a long D in a solo? To get a nice tone and vibrato, you might want to use second finger on G in 3rd position. My point is, a lot of that is up to personal preference, ability, the song you're playing, it's composer and time period, and of course the word of your teacher.

As a beginner you will probably start by playing in the first position. As you can access most notes from the first position (except for the really high ones) you don't need to worry much about the other positions just yet(for an example traditional fiddlers [even the irish ones] don't use anything else than the first position!).
The higher positions require a lot more preciseness of playing because of the violin's lack of frets, but I'm sure your teacher will teach you all this. Go ahead, have some fun with that violin .