How much money do you have, OP? Start with your budget, and go from there. I was where you are, and I started 1) budget 2) magazines 3) found an architect who helped me find 4) contractor.
I put together a file drawer with files for every aspect of the kitchen: lighting, sinks, paint, countertops, cabinets, accessories, heat, flooring, appliances, backsplash, eating area, etc. etc. I ripped photos out of magazines, xeroxed photos from books at the library, researched everything online mostly, but also did research at various kitchen stores. It took a full year, but the kitchen is perfect! Worth every minute!
If you are only swapping out cabinets and appliances, you can skip the architect, maybe just to straight to a good carpenter. Order cabinets online if you want, or get some OK ones at Home Depot or from some kitchen place.
It all depends on your budget and how much you care about the details. I cook a lot and care about every aspect of it, so it took a long time, but it's a really, really nice kitchen that works well for my family and me.