Adding a new device in IMC is fairly straightforward once you get the hang of it, but I recommend a few steps to make sure your devices are in properly.
1. Set up an Access Parameter Template
I know the first screen for IMC asks you to add a new device, but before you do this, I really recomend that you configure a templates for SNMP, Telnet or SSH access for groups of devices.
Click on System / Resource Management / Access Parameter Template. Click +Add
As per the above picture, create an SNMP and SSH template. Try to avoid using Telnet if possible as your passwords will be sent in cleartext. If you do have to use Telnet then make sure you set a different password than everything else.
Some guides below for how to configure your switches to support SNMPv3
How to configure SNMPv3 for ProVision
How to configure SNMPv3 for Comware 5
How to configure SNMPv3 for Comware 7
2. Discover your device
There are two ways to discover network devices, manual or auto discovery.
2a. Manual Discovery
If you want to add one, or a small number of devices, I recommend the auto discovery method.
Click Resource / Add Device
Put in the device IP address and name, if you don't include a name then it should pick up the device name from SNMP.
Click the +SNMP Settings button, and here you can set the template you created in step 1.
Do the same for +SSH.
SNMP allows IMC to poll MIB's
SSH allows IMC to run backups
2b Auto Discovery