That,s a good idea, making notes about where the info came from. If everyone who has put in info on their tree without having it verified, should delete it there would be rather slim trees kicking around.
Mary.
Only last week I removed over 800 people from my tree because I had acquired them via ancestry or gr and had no way to verify them all myself.
I went through each person in my tree who was of no direct relationship to me or hubby and unless they were married to a direct relation (including nth cousin x times removed) then the got removed (well to another tree - I didn't just delete them totally).
With this smaller tree of actual relations I am concentrating on finding birth/bapt, marriage, death, census, addresses, occupations for each and every one.
I use submitted IGI's as a guide only but I do accept the extracted records.
Where I don't have a cert for BMD I note the index ref, so that I can go back to it anytime.
I save a copy of each relevant census image (using it's ref as file name) and draw an yellow outline around the relevant family. Then I attach that image to each person that is appropriate.
Until I have all (or as close to all as possible) for my actual relations, I see little point in obtaining the names of parents of spouses of siblings and their lineages.
I got caught up and went too far "sideways" and my tree ended up more of a hedgerow instead, but a little pruning and it's all back under control =)