Some of what I will say has been said already, but here goes:
Yes get in, and STAY in. You shouldn't have left. Likely not only did you take money out of the market when it was at 12,000 (did you buy in ABOVE that level?), but you also have not been buying all along. If you hadn't been in the market very long, you probably took a loss by selling at 12,000. Even though the DOW is now at 9,200, you haven't really gained anything. The money you lost by taking it out and the money you will not have gained by putting it in between 12,000 and now have put you negative. My shares are down from the beginning of the year, but I haven't sold anything and in fact not only have I continued to buy, but I did one extra semi-large purchase. This bad time for the market is when you buy brother.
You CANNOT time the market. Warren Buffett cannot time the market. Put the money in and leave it there -- these should be RETIREMENT accounts. Once you are debt free (THAT MEANS EVERYTHING INCLUDING A HOUSE) and you are doing 15% or more toward retirement, if you want to dabble in non-retirement funds, then go ahead. I'm actually breaking that rule as I have retirement and non-retirement funds and contribute to both yet I still have a mortgage, but I LOVE the market so much I can't bring myself to not invest heavily in it, and my mortgage is very manageable (less than 25% of my takehome pay). If the market gets running high again, I may pare back my non-retirement mutual fund giving and attack the house. You can really do either, but the point is that initially you should be putting money away for retirement only and not non-retirement funds until all that other stuff is fully funded. With $85,000 to invest though, you probably should do SOME non-retirement funds. I would fully fund a 401k for the year ($15,500) and then fully fund a Roth IRA for the year ($5,000) and then put 3 months of expenses in a liquid account like a Money Market Account (6 months if you're married with kids) and then put the rest into a non-retirement mutual fund.
Vanguard is great. Low fees, and you never hear about them being criminal as you sometimes do with other firms. My IRA is with Vanguard. I'm down on the year, but so is everyone. You cannot go wrong by choosing funds with them.
Good luck brother. Diversify! Jim Cramer says NEVER put more than 20% into any one sector. Dave Ramsey suggests a 25% split into the following types of funds -- Growth, Aggressive Growth, Growth and Income, and International. Warren Buffett suggests Index Funds. It is really tough to go wrong with Index funds, but ultimately if you are well diversified, you'll likely do fine. Don't wait. This market COULD turn around any day, or it could drop to 7,000. You just don't know. Then, stop with trying to time things. put the money in and keep it there until you are within 5 years of retirement -- then find other ways to invest more conservatively.