Keep a personal journal. This is to protect yourself and sometimes the guilty.
Mine is several shoe boxes full of 3"x5" pocket sized spiral notepads. These date all the way back to one month after my last divorce.
They are methodically and carefully filed away (not all are in the aforementioned boxes. Some have been granted "free range privileges), under the bed, in my shop, up on a shelf in one of the closets, in the sock drawer and a duffle bag I intended to throw away 7 jobs ago...
Make inspection, scribble it down with the time. A while back I needed verification on a report. I dug thru the drawer... oops wrong drawer. Looked in another one and there was the pad (Right where I left it a month ago!) with date, persons in attendance of the inspection in question AND at 10:32 am! It was shall I say difficult for them to make a stand under such documentation. That AND I had a foto of the samples submitted to their technician (with corroborating time, the Techs left boot, and date all on the foto. [gotta love these newfangled digital cameras!]). Yep, you scan and email the notepad entry with the foto and the case is solid. PLUS you're a hero in the eyes of those up and above your paygrade. Bummed me out when I discovered how much some of them fellas make! Here all this time I thought I was rolling in tall cotton.
The particulars of each individual project dictate record keeping requirements.
My current gig has morning, afternoon, weekly and monthly meetings if which the minutes are recorded by another member of our management team.
Typically, daily reports are a requirement and submitted to some muckety muck up the food chain and cc'd to a buncha other give-a-hoots.
One piece of advice to the "Newbies". Be careful with pictures. Pay close attention to items not of primary interest, especially in the distant background. I see all sorts of safety violations (no gloves, glasses, hardhats, etc), unapproved work practices, even projects not in you companies' work scope being performed (a welder tacking up brackets for another contractor). All kinds of stuff can be inadvertently captured indelibly in a photograph. And YOU can catch the flack for not catching the offense.
Funny part is, I lost a 120 pound anvil in my shop last year. That's at home at least, not on the job. It could very well be hidden under a shoe box full of note pads somewhere....