Buffett conducted interviews Monday on CNBC and the Fox Business Network cable channels after a weekend full of events in Omaha for Berkshire Hathaway shareholders.
"Bonds are a terrible investment right now," Buffett said.
Buffett said bond prices are artificially inflated because the Federal Reserve continues to buy $85 billion of bonds a month, and owners of long-term bonds may see big losses when interest rates eventually rise. He said inflation is also likely when the Fed stops buying bonds.
He said the average investor should keep enough cash to be comfortable and invest the rest in equities.
"Stocks are reasonably priced now. They were very cheap a few years ago," Buffett said on CNBC.
But Buffett said most investors pay too much attention when the stock market reaches record highs. He said average investors should pay more attention when stocks hit records in falling prices because that's a sign they are getting cheaper.
The Federal Reserve's efforts to keep interest rates low have helped the stock market soar, Buffett said, but the improving economy has also played a role.
Buffett said he remains a fan of Fed Chairman Ben Bernanke. He also reiterated his support of JPMorgan Chase Chairman and CEO Jamie Dimon.
Buffett said the current low interest rates continue to make long-term borrowing like 30-year mortgages attractive, but he expects significant inflation eventually.
"Anybody who's borrowing money should borrow out for a long period of time. And if you ever want to get a mortgage, today is the day to get a mortgage," Buffett said on the Fox Business Network.
Buffett said he's not sure what will happen when rates rise.
"It won't go on forever and it's going to be very interesting when the first signal comes out that they're going to advance," he said.
Buffett, who heads the Berkshire Hathaway Inc. conglomerate, was also asked about aspects of that company, which owns more than 80 companies and holds major investments in Wells Fargo, IBM, Coca-Cola and other iconic companies.
He defended the way the pending $23.3 billion takeover of ketchup-maker H.J. Heinz Co. was structured.
He said he expects Berkshire to own a stake in Heinz forever, and he doesn't see a problem in taking a partner—the Brazilian investment firm 3G Capital—in the deal.
Buffett said on CNBC he doesn't consider 3G a traditional private equity firm because it is investing a significant amount of its own money and it runs businesses. Some people had questioned whether the deal that will give Berkshire a 50 percent stake in Heinz represented a change in investment style for Buffett's conglomerate.
Generally Berkshire buys entire companies outright and allows them to continue operating largely unchanged.
Buffett said he hopes Berkshire's stake in Heinz will grow over time.
On another topic, he said traffic is picking up at Berkshire's BNSF railroad as the economy improves. He said the railroad will likely deliver record earnings this year, but will probably still haul fewer carloads than it did before the recession.
"It's been a terrific acquisition for Berkshire," Buffett said.
BNSF contributed $798 million to Berkshire's $4.89 billion first quarter profit the company reported on Friday. The Omaha-based company's overall profit soared 51 percent over the previous year's $3.25 billion net income.
Berkshire's newest board member, Meryl Witmer, joined Buffett for part of the Fox Business interview. Witmer, 51, is an investment manager with Eagle Capital Partners.
Witmer said she has been impressed with all the Berkshire managers she has met so far.
"They're smart and they're happy and they love being a part of Berkshire," said Witmer, who is the third woman on Berkshire's board.
Buffett said Witmer would join the discussion on succession planning at Berkshire when she attended her first board meeting on Monday. He says succession is always the top subject the board discusses, but he said the board is unanimous about who should take over as CEO if he died tonight. That person has not been disclosed publicly.
Follow Josh Funk online at www.twitter.com/funkwrite
Berkshire Hathaway Inc.: www.berkshirehathaway.com