Noob Question about Index Investing

[Mil_Money_Muscle]

Hi all,
I'm new to this forum and was looking for a little insight. I'm interested in investing in the Vanguard Total Stock Index Fund (VTSMX) and my question is, with the indexes at, or approaching record highs, is it a good time to start investing? I'm sure there really is no bad time, but I'm looking at record stock highs and it makes me want to wait until they fall. Does this make sense? Should I just go ahead and do it? I know the stock market is a roller coaster so should I wait until it's selling at a lower price? I'm really interested in gaining more knowledge about investing and appreciate any insight. Thank you.

[arebelspy]

Short answer: unless you know the future, waiting will lose you money.  It could go down tomorrow, yes, but it could also go up.

Investing, even at market highs, has a positive expected value.

http://jlcollinsnh.com/2013/05/22/stocks-part-xviii-investing-in-a-raging-bull/

[fiveoclockshadow]

Exact question over at bogleheads today:

http://www.bogleheads.org/forum/viewtopic.php?f=1&t=119718

Short answer, go ahead and do it.  If you have weak knees you can spread out your investment over a few months - but only do this if you don't have any transaction costs.