This is not a specific site, it's a message board on the Ancestry.com (and alternatively rootsweb.com) website.
There are 100's of message boards. Maybe a bit of time reading Board Faqs and searching around the message board will help you use it more effectively. Some of this is just practicing to learn better skills.
In terms of your search, (and your tree which I looked at). Since you're a newbie, the first thing to learn early on, and you'll be happy about in the future that you did, is to not copy from other trees. Key in all your data. Other trees can have clues, but it's up to you to evaluate the validity. Keying in your data slows you down, and genealogy is a slow, thoughtful process.
All documentation is not on-line. The best thing you can do is read a "how to genealogy", either a book, or google, there are some good sites (including Ancestry.com Learning Center) that can teach you basics about research sources.
I understand you found the death record for Peter Twombly, that's good, however, data on a death record is only as good as the informants' knowledge and memory of the deceased, it's considered a secondary source. A primary source would be a marriage record, he would have given the info himself, marriage records typically list the parents.
How to find the marriage record?
Follow the bride, find where the bride's family was living at around the time of marriage, and start there.
Also, researching the baptismal records of their children can lead you to the where they might have been married.
The census helps you locate where to start looking.
I tend to lean towards trusting earlier census data, ie the place of birth. Fresher memories.
When you get into this time period and backwards, the civil records are scant. If you aren't familiar with how to use the site familysearch.org, you'll want to spend time there as well. If you've never been to a Family History Center, you find info on the site about how get film sent to your local FHC and research there.