How to effectively build a collection of books, manuscripts and ephemera
Defining collection parameters: The collecting world is divided into subject-defined and personally-defined collections. The best way I can explain subject defined collecting is by example. You can collect all the plays of Shakespeare, all the speeches of Lincoln, every book listed in the Zamorano 80, all the Grabhorn or Arion imprints. The operative world is all in subject-defined collections.
Personally defined collections are more ambitious, require more work and discipline. Here, starting with an idea and often with a date range, you evaluate all material that, from the time you begin, appears at traditional auctions, on listing sites and on eBay. It sounds daunting but is not. You can do this yourself using services provided by individual selling sites or use our MatchMaker service to scan all selling categories automatically every day for fresh material posted over-night. About 100,000 items are posted daily and the best materials disappear quickly, often without a trace. Without a way to screen new arrivals many opportunities and bargains are lost. Fortunately, even with a broad service such as MatchMaker, most collecting concepts generate less than 150 matches a day, enough to provide perspective, but which take only a few minutes to evaluate. In a few months you begin to know your area of interest well and can start to buy efficiently.
How will we buy? There are six ways:  from dealers,  from listing sites,  at auction,  at private sales,  on eBay and  at shows.
Dealers who issue catalogues will be helpful and you'll be interested to receive these mailings. Some of the smartest people in the book field issue detailed catalogues and you'll learn a great deal about material from them. Most dealers will provide perspective and advice if you are their client. If you believe their opinion is valuable be prepared to also occasionally buy from them. Other dealers list on the various selling sites. There are 22,000 active listing dealers today. About 500 issue catalogues of one type or another.
The listing sites are your next source. For old and rare books www.abebooks.com is the largest. It is approaching one hundred million items listed. Another is www.alibris.com and a third is Choosebooks [www.choosebooks.com]. Among the association sites www.ilab-lila.com is very good. As an alternative to looking at individual sites you can use a search engine that looks at many sites at the same time. www.addall.com is quite good. Initially, these sites are going to worry you because the scale of material available is daunting. Don't worry, most of what you are going to buy isn't going to always be available. In many cases, what you want to collect will only occasionally be available. On the listing sites there are of course great bargains and random rare material. In time you'll recognize these items. Initially you need to learn to see the market in a new way.