Well, it really depends upon how many live relatives you have and how much they know/remember.
At this moment i'm trying to record as much as possible from what people are able to tell me. I got an audio recorder and i do interviews of all the elderly people in my family. Just a week ago i went to the sister of my grandfather, she has turnt 90 years-old and was able to remember some things that nobody else has told me about.
Another thing that you can do is to visit cemetaries, and try to see if there're relatives of relatives that are burried nearby. Often this is the case.
ashling durkan - That is one the pluses of Geni - as you go, you can add the Profiles, and enter who told you what in the About as well as creating Documents from internet sites (that do not require log in) with info and uploading other Documents and referring to them in the About.
On the other hand - if you mean what your Dad told you does not agree with Trees you found elsewhere - basically ignore other Trees as anything other than clues of what to search for, tho if you want to mention what other Trees are saying in contradiction to what your Dad said in the About of the relevant Profiles, that may well be helpful. Either way - then go and search for actual Documentation, preferably from Primary Sources, since nobody's memory is perfect, plus we have all probably misspoken at least once in our life - plus folks coming behind you cannot tell your typo from poor info from etc - but if you have uploaded the Documentation, they can confirm for themselves that the info is accurate or what it should be.
By "internet" - what did you mean? For example --
Are you thoroughly familiar with familysearch.org ?
Do you have an ancestry.com account - and/or access to ancestrylibrary.com (free at many Public Libraries!!)
If those are new to you, then there is probably lots we can suggest. Especially if you are looking for US records. Or -- what country are you looking for records from?
For US - you can definitely get much information from familysearch.org which is available free online -- almost all the info I use from it is free and does not require logging in. It has international databases too, but I am not particularly familiar with those -- others might be more aware. But NY, yes, you can get lots of info from it.
Are you familiar with familysearch.org ?
Do not know as this is what you were looking for, but lots and lots of suggestions here:
https://www.geni.com/discussions/80238
If you have never used familysearch.org nor findagrave.com/ - would suggest those as first two to start becoming familiar with.
And for folks who died since about 2004 - check legacy.com to see if there is a free Death Notice/obit available. That often gives you info that lets you find earlier records (eg, when you know who the siblings are, you may be able to recognize the family in earlier Census Records from when they were children).
You've been given help on this, but haven't added any of the discovered information to your tree. This makes it less likely to receive additional help.
http://www.rootschat.com/forum/index.php?topic=737144.0
ashling durkan - re: "I would but i dont know the dates only names" -- Why do you feel you need the dates in order to use those? If you have the names, that is all you need. If you know within 50 to 100 years when they were born and/or died, so much the better. But you certainly do not need the specific dates to find info on findagrave or familysearch or ancestrylibrary.
You put in what information you have, and then check out the possibilities they provide - which will then give you some idea of dates. Etc.
ashling durkan - Often in findagrave memorials they list other family members, often with links to their graves. Sometimes with other information about the person.
So yes, when you put the name in, you will often get many choices for that name. But if you go thru, looking at each, you may be able to tell which is the grave for the person you are interested in - and from that get more exact dates which you can then follow-up on, and/or other family members which you can then research. [No, you will not strike paydirt every time. And even if you find a memorial for your relative - No, the information in findagrave memorials is not always accurate - but it is a good lead to follow up on.]
If all you have is there was a relative named "John Smith" - that is not particularly helpful. If you know John Smith lived in NY, was married to Mary, and they had children Susan, William, and Kenneth - that may well be enough to be helpful. Which situation it closer to yours?