Regarding fund share price before/after a dividend payout, it is a wash.
Let's say a fund is $10/share before dividend payout. At the close of the dividend day, it pays out $1/share in dividends, cap gains, etc... The next day, it's worth $9. So, it's all the same.
Well, sort of. When you consider tax ramifications, it's better to wait until after dividend payout if you are going to buy for a taxable account. In the example above, immediately after you send in $10 to the MF, the next day you will get $1 kicked back to you as dividend, which you may have to pay taxes on whether you take it in cash or reinvest it. You will still have your $10, but suddenly $1 of that becomes "income" which may be taxable. It's called "buying a dividend" and is to be avoided. If buying for an IRA, then it does not matter.
This 2013 is a good year and many of my MFs have declared and paid good cap gains and dividends. So, watch out for taxable "instant incomes" if you are buying for your after-tax accounts.