Yes. Under good guidance, you can do your own search of trademarks registered with the U.S. Patent and Trademark Office (USPTO) at the USPTO website (www.uspto.gov). For more information, see Nolo's article How to Do a Trademark Search.
You can also visit one of the Patent and Trademark Depository Libraries (PTDLs), available in every state. These libraries offer a combination of hardcover directories of federally registered marks and an online database of both registered marks and marks for which a registration application is pending.
In addition to searching for registered or pending marks, you may also use product guides and other materials available in PTDL libraries to search for possibly conflicting marks that haven't been registered with the USPTO. This can be important because, even if a mark is unregistered, its existence could preclude you from registering the same or confusingly similar mark in your own name or using the mark in any part of the country or commercial transaction where customers might be confused.
In addition, you may want to review merchandise at an online store. For example, if you are selecting a trademark for a new toy, you can visit "ToysRUs" at www.toysrus.com. Once there, you can browse hundreds of toys and do a keyword search for any toy trademark that is similar to yours. This same approach can be used for any type of product by clicking the shopping category link on one of the popular search engines, such as Yahoo.com.
While you'll no doubt find hundreds of similar trademarks being used across the country, you'll need to know how to sort through your search results and determine which trademarks you are prevented from using. For help doing this, see Trademark: Legal Care for Your Business & Product Name, by Stephen Elias (Nolo).