I hadn't done much in the past, but coincidentally I'm now slowing moving on a track like this myself. On and off for many years I've been thinking about doing this for our family. My one younger brother and I were born in Austria since my parents decided to escape from Hungary late in WWII after having endured the insanity of the Germans earlier and not wanting to find out what the Russians would do since they were now coming from the other direction. So they ended up in a camp in Austria, under the Western Allies, for people displaced from other areas of Eastern Europe. My brother and I were born there, then a few years later we all came to the U.S.
Just a few weeks ago, I saw a small article in Newsweek which mentioned the ancestry.com site you also bring to our attention, saying that the site now has data from something like mid 1800's to late 1990's on almost everyone who immigrated to the U.S. from other countries. So that day I went to the site, put in my dad's name and some related data about arrival and up popped a list showing my dad, my mom, my younger brother and me, showing when we arrived, names, some other data. So I emailed it all to my siblings and a couple relatives and it started a nice little exchange of memories and further efforts to find more information. Last year my daughter was exploring Europe and went to Budapest and found the address where my dad lived when he was a young, up-and-coming artist already of some notariey; we found that address from postcards he had made up with his name and address imprinted and one of his paintings on the front. She knocked on the door and after some misunderstandings about whether her grandfather lived in the house or not, eventually communicated the facts and got a friendly welcome from the current residents. I'm still planning to follow further trails and go back further and further to see if my great great great .....great grandfather was maybe Attila the Hun

the much maligned but great and honorable revered hero/leader from Hungarian history. One of my favorite traditional paintings of my dad's was his "Attila Temetese" which is Attila's Burial in the riverbed of the diverted Danube River, that painting was purchased by some political/post monarchial family, not the Hapsburgs but one of the other of those old world names from Austria-Hungary.