in Linksys routers it comes under Access Restrictions. (in factory default firmware).
feasibility and options in restricting machines/PCs connected to the router is dependable on the router's functionality and its firmware.
normally in Linksys routers their are less options for administrators to restrict the connected machines for any kind of data transfer.
login to your router web interface. get in the Access Restrictions.
you will find a limited free set of policies to be defined as per your rules. but that's all you can not define more than that in your current factory firmware.
it's up to you how do you use one policy to handle more machines. normally following functions you can perform to restrict one machine or more than one machine in a single policy.
-You can tell in the policy which machine(s) are you willing to define following rules for.(via Mac address or a set of IPs or a range of IPs of limited number of machines )
-completely allow/deny access to the internet for one or more machines.
-define on which days the access to be restricted.
-define the time or time range when to allow or deny the internet access.
-block a set of limited specific services like HTTP, FTP, TELNET, POP3, SMTP, etc.. when allowing some machine(s) for the internet access.
-block a limited set of websites by URL when allowing some machine(s) for the internet access.
-block the websites or content by a limited set of keywords when allowing some machine(s) for the internet access. keywords might be like specific to heavy bandwidth, adult or violent content. for example. "youtube" "nudity", "sex" etc.. the keywords are matched with the words in the URL not in the resulted webpage content.
you can observe that I made the term limited bold where used. that's why the default factory firmware for Linksys routers provide only limited functionalities for its users AFAIK.
you can try third party firmwares any way to have more and possibly unlimited options for access rules.
about Monitoring, you can enable/disable log in the Log under Administration
you should change the topic title from "Monitoring Wireless Router Access" to like "Monitoring/Restricting the internet access via Routers"
your title seemed to me first as you were looking for restricting the access of Router's web interface from specific machines