The best way to plan is to start at the beginning. The two most crucial determining factors in planning your event are the why and who. Why are you planning an event and who are you going to invite? Events could be anything from a baptism to the Superbowl, while you could be inviting friends, co-workers, family, etc. This will help you with your theme, unless you are having people over just to have people over. In that case, you will determine your theme. The theme will translate to the components of your event.
You should start dividing your event into components- food and beverage. Determine which of these is most important, then pair the other off that. Superbowl party with wings and dogs? Grab some beers, wines, and other refreshments to compliment. Inviting others over for some bubbly? Pair up some rich cheeses or dessert.
Once you narrow down your options, get your source. Are you going to cater or cook? Delivery or pick-up? Search your local area for the best vendors and help. Use the advice of these "experts" along with some internet research to finalize your selections.
Finally, you've reached presentation. Survey your space and configure everything to make access easy for your guests. If you have a large kitchen, that can be an ideal place to stage the food and beverage- there should only be ONE spot to retrieve both. This will also hopefully be your main social area- a central area will make for easier cleaning afterward. Make sure a bathroom is close and accessible. And provide entertainment- throw on a movie or sporting event in an alternate area. When people want a small escape from socializing, a television is ideal. Also, make sure your guests will be able to get home safe. Not only are you possibly legally responsible, but morally as well. They are, after all, your guests.
If you are having any difficulty, consult some experts, like the Windy City Wine Guy. You may have to pay a bit for some help and advice, but this will be further assurance that your event will be a success. No matter what you do, if you follow these steps, you and your guests will be having a delicious and wonderful time. Take pictures and grab your bragging rights!