I have little to non Mass Effect experience, I touched on the first one for a couple of hours but I remember almost nothing.

So now I'm so hyped for 3 and I wanna play right now. Should I play 1 & 2 before?I didn't inted to.. I played the demo, which turns out is the begging of the game and there I had to sacrifice one of two people Ashley or the guys (who's name I don't remember), could I save them both by saying I find numerous victims as a significant lost and will this kill other main characters of my squad. Also is there some way that they dont' take my ship and strip me out of comission if I play the first and second game. If you're a newcomer to the third does it give the best possible beggining?Also I noticed in the demo they had me choosing a class, I thought it was the same, but when i played the multiplayer I realised Vanguards (for example) had unique powers. If I choose soldier as a class in the single-player can I acquire the Vanguard (or other race) powers or is it limited?

If you play through to the end of Mass Effect 1 you will enjoy 2 more if you play to the end of 2 you will enjoy 3 WAY more. That is beyond question...Will take a good 40-60 hours to do a "complete" -ish play through combined though. I've finished them both, lost the saves, not sure I've got the will power to start again though I really want to.

Would strongly recommend playing through ME and ME2 first. For background knowledge and a better ME3 experience.
Dunno what fillet did the whole time, but 40 hours at most for both. (DLC excluded)

I'm pretty sure it took me 14 hours for ME and 25 hours for ME2 with some DLC, so probably 23 hours without any DLC.

Thanks for the answers
Yeah I might play them, but ME 1 and ME2 and the DLC will cost me money and time and I wanna play ME 3 pronto. Game comes out on Friday here, so can I wanna know if it's worth effort to play them. Can I save my rank in the Conseil and my ship and can I have both Kaidan and Miranda(without playing ME1 & ME2)?