After how woefully lacking in detail for the novice in OS 10 switches the Dell documentation is below is a little snippet that can be used to configure your switches with what appears to be enough permission for PRTG (or a similar SNMP monitoring system) to keep an eye on them.

After entering configuration mode a readonly view with a base OID is set (I’d be grateful for some feedback on this!), then a group (prtg) is created to contain the user and defines readonly permissions, finally a user (prtguser) is created, assigned to the group (prtg) and the relevant password and privacy encryption strings set.

snmp-server view readonly included
snmp-server group prtg 3 priv read readonly
snmp-server user prtguser prtg 3 auth sha LONGANDSTRONGAUTH priv aes LoNGANDSTRONGPRIV
write memory