Does your employer provide a matching contribution to your 401k? If so, contribute enough to the 401k that you can fully take advantage of the 401k match (e.g. if you employer matches 3% of your income, contribute 3% of your income). It's free money, take advantage of it.
Next up, max out your Roth IRA. The limit is $5000 currently a year.
After maxing your Roth, revisit your 401k. You can contribute up to 16,500 per year.
You savings account is a good place to keep a rainy day fund (do you have one?), but it lacks the tax advantages of a Roth IRA or 401k, so it is not really suitable for retirement savings (unless you have maxed out both your 401k and Roth IRA).
Once you have take care of getting money into your 401k and Roth IRA accounts, the next step is investing it. The specific investment options available to you will vary depending on who provides your retirement account(s), so these are general guidelines.
Generally, you want to invest in higher-risk, higher-return investments when you are young. This includes things like stocks and developing countries.
As you get older (>30), you should look at moving some of your investments into things that less volatile. Bond funds are the usual choice. They tend to be safer than stocks (assuming you don't invest in Junk bonds), but your investment grows at a slower rate.
Now this doesn't mean you immediately dump all of your stock and buy bonds. Rather, it is a gradual transition over time. As you get older and older, you gradually shift your investments to bond funds.
A general rule of thumb I have seen:
100 - (YOUR AGE) = Percentage of your portfolio that should be in stocks
Someone that is 30 would have 70% of their portfolio in stock, someone that is 40 would have 60% in stock, etc.
As you get closer to retirement (50s-60s), you will want to start looking at investments that are more conservatie than bonds. Start to look at fixed-income and money market funds.