For whatever reason you only have four weeks to plan your wedding in, this month can be time enough. Providing the essentials are all in situ, you can play with whatever time you have left to make it the very best of days for yourself.
Naturally, the very first thing you need to do is book the ceremony and reception. If you are choosing a church service, you will need to make arrangements as soon as possible. Some establishments have a 3-4 week wait after application. If you are booking a formal registry office ceremony, you will still be wise to organize this as soon as you can, just to make sure you do not plan everything and then have to shift the date! If you plan on booking a location wedding, once again, time is sometimes a factor. Whatever your decision for venue and style, the ceremony should be the first thing organized and the reception a close second. This may be as simple as two phone calls, or may involve organizing an appointment to discuss matters or pay a deposit.
Once you have the service and reception booked, you are free to fill in all the extras. Guests are usually required, so invitations might be the second item on your agenda. Purchasing a packet at the newsagent or discount store, or creating your own invites on the computer, you will probably still need to run down to the post office to settle the postage matters. This can still be fitted into the first day's plans, although filling out the invitations may be time consuming. It might be a fun idea to sit down together over a few drinks or a special meal and write them out together. That saves losing any together-time with your upcoming spouse.
Other matters that need attention include your clothes, cake, flowers, music, meal and drinks. If you want a new dress, rather than having a family heirloom or special dress in mind, it may take a while to decide on appropriate attire. Asking family members if they have a family dress to borrow can save time, and if you run out might be an option to save the day. If you catch it in time, you can browse the local wedding stores, online catalogs, department stores, etc.
The cake also needs prior contemplation. Whereas some couples opt on a gourmet or special design, most have a tiered white cake with wedding decor. This will need to be booked at the cake shop, as a baker cannot whip it up in two hours flat if you forget until too late. A month is plenty of time to book the cake in, though.
Try to catch the florist at a time when they are not too busy with other customers, or visit their website and leave a message. Try to order all the flowers you will need at one place at the same time, to save yourself time and effort. You may discuss the music with your clergy, if holding a church ceremony. Most location weddings will opt for a live band, recorded traditional tunes, or going without music. You will probably need music supplied for your reception, however. Hiring a local band you both like, a band a mutual friend is in, or a DJ who is forewarned your favorite tracks will also need pre-booking. Once again, this is usually just a simple phone call.
Finally, contacting a catering company is a good idea. You will need to know the prices and make a booking in advance. If you are on location, you will need such as appetizers and champagne, if nothing more. For a reception you may just want to stick your Aunt in the kitchen and get her to bake her special pies and dump some chips in a bowl, whilst concentrating on the drinks. On the other hand, it is a great excuse to splash out a little and order in something special. Many couples opt for a bulk-buy package from a favored restaurant, a catering company, or a family member who adores cooking. You can always phone the pizza store if you do forget to book food though. They will be sure to enjoy having a 20-pizza order surprising them!
Out of all the essentials, these matters need to be seen to as soon as possible. Other matters such as who will be best man or bridesmaid can slot into your second week of preparations, if they do not fit the first. You will probably need the middle two weeks to organize the details of everything you started.
Using the final week to add finishing touches, sort out any problems arising, and add last minute touches - such as balloons or streamers, place mats, napkins, etc - you should have your wedding planned, organized and prepared, all within a single month.