TWENTY YEARS AGO, A YOUNG company didn't need to worry much about buying office equipment or business services. The copier came from Xerox, the typewriters from IBM, the phone system from you-know-who. Fineries like overnight delivery services and bargain air fares were things of the future.

Today, of course, a company has dozens of alternatives -- and dozens of sales pitches -- to sort through. A little help with this sorting can now be had from What to Buy for Business, a 10-times-a-year, no-advertising magazine launched just last June.

What to Buy for Business was born almost by accident. "When my partner and I started our original business," recalls John Derrick, a 29-year-old Englishman who is the publication's managing director, "we needed advice on purchasing and looked around for a consumer guide for business." Finding nothing, they chucked their initial venture and set out to fill the gap. The result: a British edition of What to Buy, which over six years grew to a profitable circulation of 11,000. Late last year Derrick opened an office in Rye, N.Y., and began preparing a U.S. edition.

To judge from its first American issues, What to Buy is comprehensive, candid, and useful -- up to a point. An 85-page report on copiers, for example, covered nearly 200 models, offering assessments ranging from complimentary to, well, blunt ("arguably the world's worst copier," one model was judged). The report included a hefty dose of inside dope on the copier business. You're buying from Xerox? Expect a piddling list-price discount of 7%, as compared with the 20% to 25% most other companies offer. You like the Pitney Bowes D500? Try the Ricoh FT6085 instead -- it's the same machine, bought from Ricoh and relabeled by Pitney. According to last June's issue, you could get it from Ricoh for about $1,700 less.

The publication isn't yet on a par with, say, Consumer Reports. Derrick's staff is tiny, and his evaluations rely on user surveys and staff assessments of a product's capabilities, rather than on extensive testing. That said, an annual subscription at $95 may still save more than a little time and motion for anyone interested in reports on everything from word-processing software to the best deals in business travel. "In a small business," Derrick points out, "it's often the boss who does the buying. He can go in for cross-your-fingers-and-hope purchasing, or he can research all the options while neglecting his main business." Maybe if he reads What to Buy for Business the choices won't be so stark.