Crochet help!

Right-o, I've finished all these granny triangles, blocked them and love them all to bits. So far, so good. But I have a problem. I don't know how to put them all together in a near straight line. Kinda like in the picture below, only in a proper straight line, not like the curve there, that's just because the ironing board isn't long enough. ;-)

I tried single crocheting them together, but that made the triangles buckle because (I think) they are not all the exact same size. Then I tried something with double crochet. I tried crocheting them together point to side, but couldn't get that to work either.

Right now I'm really feeling my lacking experience with crochet, which, to be honest, is almost zero. And since there are no granny triangles in any of the crochet books I have, there's no help there...

I feel like I'm THIS close to finishing this scarf, but I just can't seem to get it right. I want it to be pretty and sweet and just right for spring... So, if there is anyone who can give me some kind of advice on how to do this, please, please get in touch!