@Daisymh: Very good question. Here is where you start.
There are three very important things that you have to do, each is interdependent, and each will determine a lot about how the whole wedding is going to shake out. Work on these three steps at the same time:
1) Vision. What kind of wedding are you envisioning and what are the (FEW!) most important things to you and your husband? I suggest you two make a short list on the few items that are absolutely most improtant to you (example: Saturday night, open bar, designer dress, etc), and then another list on things that don’t matter too much (example: showy centerpieces, live band, Saturday night, open bar, etc). You’ll need this to remind yourself of why you refuse to stress out over flowers (or wahever was on the unimportant list) later.
2) Guest list. Sounds like you’ve got a handle on this. THere is no point in planning other elements if you don’t know how big of a party you are trying to throw.
3) Budget. What are you realistically able and willing to spend? Will you have help from others or will you be footing the bill on your own? The budget will be rough at this stage, but you’ve got to figure out what ballpark you are working with.
I’m sure you can see how each of these items are interdepenent. If your vision is an elegant evening at a 5 star hotel with all the celebrity trimmings and your budget is $5k, you are going to be in trouble. If you want an intimate affair, but you have 150 people on the “close family” list you are going to have an issue. Etc.
After that I think that venue is the first step. Venue will determine how you spend most of your budget, will set the tone for the event, will determine the final date, etc. Once you have the venue a HUGE piece of the planning is done, espeically if your venue will provide the catering, set up, linens, etc.
If you are looking for a good resource because you don’t know where to start, I suggest the book A Practical Wedding by Meg Keene. Very good stuff. She has a website, but the book is more of a guide to getting the wedding planning done. The website is YEARS of content, so I think the book is a better starting point.