Function
The first question to ask as you're developing your kitchen remodeling plan is: "What drives me crazy about this kitchen every time I'm in here?" Think both big and small. Do you need more storage space? More seating for your family? More light switches? A spray hose for washing dishes? Make a list of everything that would make your kitchen perfect. Include both the absolute needs... "I can't wash another dish by hand. I need a new dishwasher!" and maybe even a "want" or two... "I would love a great kitchen stereo system to listen to while I slave away over a hot stove!" Once you have your list, you can move on to the next consideration.
Aesthetics
Kitchen renovations are never just about function. They're also about style and design. Who doesn't want a drop-dead gorgeous kitchen? Some things to consider about your kitchen's appearance: Are you tired of dark cupboards? Do you want smooth marble countertops? Are you ready for some stunning Mexican tile flooring? You can turn to all sorts of places for aesthetic ideas including books, magazines, friends' kitchens. Clip pictures of what you like and make your own "dream book." This is a great way to find out what looks appeal to you. How well do your "needs" list and "wants" list mesh? As you begin to see how those lists can fit together, your kitchen remodeling plan will start to take some shape.
Feasibility
Once you know what you want your kitchen to do and what you want it to look like, you've reached the hard part of kitchen renovation planning: facing the question "Can it be done?" This question has several components. The first is structural. Sure, you want to knock out that wall and open up your kitchen to your family room, but is that a load bearing wall? The second is financial. You just love that expensive Italian marble, but you also need to be able to afford food to put in your new kitchen, so Italian marble is out. Can you afford to hire a remodeling professional? Can you afford not to? It's a game of trade-offs. Spring for the tile flooring, cross the bay window off your list and a plan starts to form. When function, aesthetics and feasibility merge, your new kitchen can become a reality.