It's that time of the year again to plan your Holiday party extravaganza. It can be overwhelming for anyone, even the experienced planners. Here is the breakdown of your time line and what needs to be done to plan a perfect party.
My best advise would be "Start NOW!"

3 to 4 weeks ahead: 
Decide how big of an event it's going to be. Map out the guest list and decide if it's going to be a standing or seated affair. Also, send out your invitations at this point -- you want to make sure people have enough time so they can make room in their schedules.
1 to 2 weeks ahead: 
Plan the party, menu and gather any special equipment that you may need. If you're not pulling out the fancy silverware then consider the compostable tableware items and buy the needed beverages since they can be bought ahead of time without going bad. This is also a good time to clean and press the tablecloth and/or cloth napkins.
3 to 5 days ahead: 
Clean the house. This endeavor can take several hours in itself so leave a large chunk of time for this part of your planning.
3 days ahead: 
Prepare your grocery shopping list and go shopping. Leave extremely perishable items for the last minute, but gather everything else at this point. If you already know you won't have the time to cook, you can also opt for the easy way out and hire a caterer. A lot of caterers will provide you with a set meal option or do something different with an array of yummy appies (depending if it's a sit down dinner or cocktail party)
1 to 3 days ahead: 
Prepare any make-ahead recipes and store them in the refrigerator or freezer.
1 day ahead: 
Decorate- the fun part! Glam up your house with bright colors or glittery decorations to make it feel festive. Set up your bar/beverage area and prepare garnishes. 
Day of party: 
Prepare the remaining recipes (or confirm delivery time with your caterer), and add finishing touches to your dishes that you made ahead of time. Be sure you have plenty of ice on hand as well as have the beverages cooling in the refrigerator.
Take a last look through the house, take a deep breath, and remember to enjoy the festivities!