Tired of squinting at census microfilm? When microfilmed indexes and Sounds aren't yielding answers, try a Web site offering searchable census indexes linked to digital images of the original records - which opens up new ways to look for your forebears. The two best, most comprehensive online collections:

• Ancestry.com <Ancestry.com > offers images and every-name indexes for all available censuses, 1790 through 1930 (remember, however, that the 1790 to 1840 censuses name only heads of household, so others don't show up in the indexes). Search on any combination of first name, last name, state, county, township and mother's or spouse's given name. You can specify an exact search or use the Soundex system to find variant spellings. For later censuses, add (depending on the census) a birthplace, birth year (plus or minus up to 20 years), marital status, gender, race, immigration year (plus or minus up to 20 years), father and mother's birthplace, relation to head of household, and keywords.

• HeritageQuest Online <heritagequestonline.com>, available free through many public libraries, has images for all the censuses plus head-of-household indexes for 1790 through 1820, 1860, 1870, 1880 (partial), 1900 through 1920, and 1930 (partial). Search options include first and/or last name, state, county, location, age (with a 10-year range), sex, race and birthplace.

If you've tried a simple search at one of these sites and come up empty, don't fret - you've only just begun. Use these strategies to wade through the Web of records:

1. Search for different spellings. Your ancestor could have assumed any number of identities in the census, so try a Soundex search and spelling variations. Then try Omitting the first name; your ancestor James may have been enumerated by his initials, the nickname Jim or the abbreviation Jas. You can even use this approach to hunt for possible ancestors you didn't know existed: Look for every body with the right surname in the right time and place to be an ancestor's missing parent, then try to make the link.

2. Skip the surname. At Heritage Quest, you can search by first name only - for everybody named Joel in 1820 Surry County, NC, for example. Especially for early censuses with fewer total entries, that can be an effective strategy (there are only five Joels in 1820 Surry County — one of them my ancestor with his surname misspelled).

3. Omit the name entirely. Ancestry lets you search without entering either a first or last name, which can be more useful than you might think. You can start by casting a pretty wide net here, then narrow the search if you're swamped with hits. For example, you can search on a residence and place birth, as I demonstrate on the next page, then specify an immigration year, spouse's name or other parameter.

4. Switch sites. Each census service has slightly different options and indexes. So if you're lucky enough to have access to more than one census site, try your stumped search on another one. At Ancestry.com, I had trouble finding my ancestor Oscar Lundeen because his name was misspelled. But HeritageQuest had him transcribed correctly, so I found him there on the first try.

5. Find family and friends.

When you strike out searching for your ancestor in Ancestry.com's every-name indexes, try looking instead for siblings or children in the same household. If I'd searched instead for my grandmother Olga Lundeen in 1900, I would've found the whole family right away.

As a last resort, if you've found an ancestor in one census but come up empty 10 years earlier, try looking for the neighbors' names. They may still live near your elusive kin, or the whole neighborhood may have moved from the same place. With the power of online census searching, there's no reason ever to save “I give up!”