Here's a no frills cheat sheet for a quick vPC and FEX configuration on a pair of Nexus 5000 switches. Refer visio for switch connectivity.
Note, my management network is a /29, just in case you want to configure config-sync between the two NX5K switches. You will need a cfs mcast-address which could be the same as the default gateway used in the management vrf.
On NX5K-1
int mgmt0
ip add 1.1.1.2/29
vrf context management
ip route 0.0.0.0/0 1.1.1.1
int eth1/1-2
desc vPC Peer-Link members
channel-group 1 mode active
int po1
desc vPC Peer-Link
vpc peer-link
switchport mode trunk
sw trunk allowed vlan list
spanning-tree port type network
vpc domain 100
peer-switch
role priority 4096
system priority 4096
peer-keepalive destination 1.1.1.3 source 1.1.1.2 vrf management
fex 100
desc "FEX 100"
pinning max-links 1
fex 101
desc "FEX 101"
pinning max-links 1
int eth1/9-10
channel-group 100
int eth1/11-12
channel-group 101
int po100
switchport mode fex-fabric
fex associate 100
vpc 100
int po101
switchport mode fex-fabric
fex associate 101
vpc 101
On NX5K-2
int mgmt0
ip add 1.1.1.3/29