At any age and any income level, I believe that 75% to 85% of your savings should be in mutual funds. Not just any mutual fund though.
The best fund be right now is the vanguard index funds, why? because they are the easiest and the cheapest to control and maintain plus they mirror the markets.
(1) While most funds charge as much as $67. per $1000.of savings for fees, the vanguard funds cost 0.18% or $1.80 for every $1000. of savings.
(2) Because these funds are index funds they will do as good as the market does.
(3) Here is how I would brake it down:
15%-20 % of your money into the US large cap index funds,
15%-20% into US small cap, index funds,
15% -20% into emerging markets index funds,
15% into Asia pacific index funds,
15%-20% into euro index funds,
10% into the mining and natural resources index funds and
10% into precious metals index funds.
If you set up your savings like this you will only have to check it once or twice per year.