I just went through this setup myself. If you complete newbie - it might be too much to handle.
But in a nutshell - it is done via Logging capabilities of Mikrotik. And there is 2 ways to approach. And you don't get any kind of "reporting" with stats, etc out of Mikrotik. Mikrotik has all the tools to help you collect data. Visualizing/analyzing/reporting is on you (other software)
1. Reverse proxy. Enable reverse proxy(millions of tutorials) and log data. It will give you all HTTP (unsecured) traffic. You will be able to see exact URLs.
It's nice because you can tell from URL what it is.
It's bad because SSL (HTTPS) will not be there. And more and more sites use HTTPS
2. Forward packets to "Log" on firewall level. This will give you IP from and IP to info. So it's very detailed. ALL activity will be captured.
It's nice because every single packet is captured
It's bad because:
a. You need to lookup IPs. For internal addresses it's easy (I assume you know which PC uses which IP)
b. You need to lookup IPs. For external addresses pretty much impossible. You can use DNS lookups but it will give you s1.amazonses.com instead of
www.someinterestingsite.com. There will be a LOT of IPs.