Let's assume you have decided not to buy a ready to assemble (RTA) home bar but install a custom home bar. You need to determine if you are going to build it yourself or if you are going to hire a contractor to do it. This will depend on the amount of free time you have vs. the amount money you have to spend. The size of the project and you time frame will also factor into who builds your home bar.
Hiring a Contractor:
If this is going to be a big project we strongly suggest using a general contractor. They will handle all the plumbing, electrical, carpentry, permits (if needed) and cleanup. The contractor will work with you as far as design and alert you to any potential problems beforehand. These guys are worth their weight in gold and will probably get the project done sooner than having to rely on Uncle Bill who used to do some electrical work back in the day.
Have your wish list ready and some rough drawings done when they come to do an estimate. Estimates are usually free and I would suggest getting at least 3 of them. They will come back to you with floor plans, a contract and a dollar amount. Read the contracts over carefully. Make sure EVERY element you wanted is included in it. You should also hold them to a timeline for the completion date. Make them spell that out in the contract along with a penalty clause if they don't. Any reputable contractor will be ok with this. Beware of the guy who has six jobs going at once. You want them to show up everyday at your house and work, not spreading themselves too thin.
One major piece of advice.... get all the refrigeration, sinks and larger items that need to be installed BEFORE the contractor starts! Have all these pieces in your possession before they start working. This will eliminate any nasty surprises like thing not fitting, doors not having enough room to open and spacing issues. The contractor will not have to guess as to the measurements; they can simply walk over to the piece in question and measure.
Building the Bar Your Self:
If you are fairly handy and want to build your own home bar or have a bunch of friends over to help be sure to have drawings and diagrams of the how the bar should look hanging in multiple places to make sure that everyone is on the same page. Depending on where your workshop is, or if you have one, you will need to figure out how to get every piece of the bar from your shop to the bar room. You may want to consider buying the armrests and bar foot rails instead of trying to make them yourself.
A few other tips and suggestions if you are building your own Home Bar: