(FORTUNE Small Business) – These are sweet days for deal-hungry entrepreneurs putting their firms on the selling block. At this time last year, small-business owners were lucky even to find a serious buyer--let alone one willing to pay their asking price. Now, with an improving economy, low interest rates, and rising business confidence, Main Street is roaring back. In the first quarter of this year, the value of U.S. mergers and acquisitions hit $310 billion, compared with $85 billion during the same period last year, according to Dealogic, a London research firm. "There is pent-up supply and much greater demand for smaller businesses than there was a year ago," says Mark Filippell, head of KeyBank's M&A department.

What's more, this boom is being driven by a new trend. Explains Filippell: "Now there's a much wider variety of buyers, which is driving up prices." In some cases, European and Asian companies are taking advantage of what they consider a weak dollar to snap up small and midsized U.S. companies. Then there are the venture capitalists and other private-equity funds that, having sat out the post-bubble years, now seem ready to get back in the game. "They've got $80 billion to $100 billion raised," says Filippell, "and they're in a rush to put their money to work."

And a third class of buyers has emerged: small businesses eager to expand their reach through acquisitions. Why? To meet the demands of giant clients such as Ford, Starbucks, or Wal-Mart, these firms feel they must expand. As Alan Scharfstein, president of the M&A firm DAK Group in Rochelle Park, N.J., puts it, "Companies want to be more important to the corporation they're selling to--they want to be able to service that client nationwide."

So how does an entrepreneur who wants to sell a business take advantage of this new wave of M&A? Some, including Dean Clarke and Keith Spencer, owners of Hi Mountain Seasonings, a Riverton, Wyoming maker of beef jerky seasonings, decide to advertise their company nationally. After the pair put a $2 million pricetag on their 12-year-old company last year, they had their broker circulate the news far outside their local market. They plied private-equity investment groups with information on the company and pumped business trade publications and the Wall Street Journal full of ads. The result: After a starting bid of $2.4 million, Hi Mountain Seasonings was sold to a Connecticut couple for $4 million. "Seven serious buyers flew out to Wyoming to meet with us," boasts Bob Balaban, Hi Mountain's broker.

Selling your business nationally can be a daunting task, but help is on the way. New websites and newsletters such as MergerPlace and Mergers & Acquisitions Advisor are sprouting all over, offering consolidated data on deals, organized by region and industry, and often hosting educational and networking conferences. "Banks have cut back on their coverage, and now that the merger wave is back a lot of banks don't have coverage of small and midsized companies," explains Josh Kosman, editor-in-chief of the newly debuted North American edition of Merger Market, an online magazine that tracks mergers and acquisitions.

A small but growing number of entrepreneurs are saving time and money by selling their businesses online. BizBuySell.com, launched in 1996, boasts 20,000 listings, making it the largest online marketplace for private small and middle-market companies. In addition to selling data the organization has collected on recent deals, BizBuySell offers a standard business-for-sale ad for $69 for 60 days. The website will keep the selling firm's identity private until it chooses to reveal itself to a potential buyer. Victoria Ring of Columbus, Ohio, says she sold her two small legal-services Internet companies, each with less than a half-million in revenues, within a week of listing them on BizBuySell.com. "It was just so quick--I got a faster response than I get when I try to sell stuff on eBay," Ring says. "It would have taken at least a month for me to market them myself, and it would have been so much more expensive with a broker."

Sellers seeking foreign buyers might consider Entrepreneur's Place, an online service aimed at companies with revenues around $5 million. Firms from some 30 countries are represented in the site's 16,000 listings. "It's not uncommon for a manufacturer of a widget in Asia to look for a southwestern U.S. producer so he can avoid U.S. tariffs," says CEO Scott Long. And who cares if a buyer pays in yen or dollars, as long as the price is right?