1) To start off you really have to limit the search to a few people. In the case of Morris Steinberg, I knew that he had come over to Phila in 1900 at age 3. How did I know this? I found the naturalization papers for his father at the national archives in Phila. OK. Lets be fair. YOU may not have any such records. If you have an uncommon surname you have a decent chance of narrowing things down. If you have some records it makes things that much easier.
Not to be morbid or anything, I usually try to search from the grave on backwards. If I can find a grave, I usually will have enough info to get a death certificate and possible get some c/o info out of the cemetary office. This c/o info depends on the weather. If its a stormy day forget about any help. How do I get to the grave?
2) A Very useful tool that I've been using for some time now is the LDS Mormon Ancestry Social Security database. (see link below)...