The first step in managing private clouds is to get management tools that can bridge the physical infrastructure and the virtual infrastructure. You will have to manage physical servers running no virtualization software and physical servers hosting virtual machines, because not all servers are likely to be resources in the private cloud.
You'll want to choose software that provides you with a consistent environment -- whether you are running a workload on an operating system platform (with or without virtualization) or running an application in a private cloud. In other words, choose tools that let you see the same view across execution environments.
You also want the same type of consistency for software licensing across all of the environments in which you are running applications -- private and public cloud, etc.
Infrastructure management includes managing VMs, storage, backup/recovery and so on. Vendors that sell tools here include Abiquo, Nimsoft, 3Tera, Terremark, CA, Cloud.com, Enomaly, Citrix, Platform Computing, Red Hat, Microsoft, Surgient and VMware. While vendors often claim that their products are targeted for private cloud infrastructures, they sometimes use a very loose definition of 'cloud.' You should use caution and carefully investigate the functionality of each product.
Another thing to consider is that small firms and some medium-sized enterprises often do not have the skill sets and experience to take on the task of building a private cloud. These organizations would likely need to hire an IT consultant.
There is a second layer of management, service-level management, which involves managing workloads at a level of abstraction above virtual servers. This is where automation is applied. It is also where traditional management tools such as IBM Tivoli and HP InSight work within the private-cloud stack. The list of vendors that claim to have automation-management tools includes IBM Tivoli, HP, CA, Oblicore, LineSider Technologies, DynamicOps, VMware and BMC.
Private clouds in smaller businesses
The trick to implementing a cloud in smaller companies is to make it act like a cloud but not look like one.