Adding a Second Subnet for Virtual Server IP's

We have a more complicated way to add the vLANs and it's my first time to add a new subnet. I see tagging and external vlans. I see also new subnets on the F5 for self IP and float since we have two Big IPs and HA. Where can I find a step by step procedure since I've never done this before? I added the Self IPs self and float. created a external vlan for new subnet. New vlan showed in the route domain list. Something however is reflecting the new pool with Node in the new subnet not reachable