Because how else will people know to come?! You gotta send them invites! And this isn't something you should scrimp on, either. Your invitation is the face of your event. The first impression people get of what to expect and if they should even come. It's gotta be good.  Consider your typical invitations -- postcards, flyers, etc. But also go paperless: email, newsletters, Facebook, Twitter, and sites like Eventbrite that serve as invitations, guest trackers, and a calendar. Correction: if you're trying to get as many people to come as possible, definitely use Facebook and Twitter. If you're trying to keep it to VIPs only, avoid these platforms. That's just asking for trouble. You'll need a headcount to know just how much and what you all need, so keep track! It probably won't be the number that actually show up, but it should give you a general idea. Websites designed for event managing can help you do this -- but so can Facebook and an Excel spreadsheet. Will you need to find, hire, book or delegate  photographers, builders, designers and decorators, guest speakers, sponsors, entertainers or bands, officiates or clergy, dancing partners or demonstrations? It is wise to include them in catering and seating calculations so that a meal and a table place is provided for them if appropriate or required, too.   Are food and beverages provided? If so, know who will be on the team to look after the cooking, serving and cleaning. What type of food do you need to serve? Are there likely to be guests with allergies, vegetarian or vegan needs, diabetics, religious needs such as halal or kosher, gluten-free, (etc)? And will there be infants, young children or the aged or injured who cannot eat solid foods? Are entertainment and logistics organised? This part might be delivery of music equipment, pavilions or tents and decorative effects or stage management you will need, such as a microphone and amplifiers, lighting, power outlets, projectors and screens for slideshows, smoke machines or other stage magic effects such as mirrors, banners and corporate signage, etc.If you subcontract a company to be entertainers, consult with them to ensure they are able to supply and set-up their own equipment as well as where the stage and service sections will be on the site and what the schedule will be. This way you can find out what you may need to do to assist them.  Caterers, florists, entertainers and other important people appreciate as much time as possible to plan, as it is typically more expensive to obtain goods and staff for high urgency requests. The other advantage is should they not be able to keep your appointment, you have some time still to find an alternative. The MC doesn't always organise the event entirely, but they do host the event. It is usually a member of the party, who will organise speeches, announce events such as the meal courses, dancing, notable guests or entertainment. Liaise with this person often and keep them up-to-date. If they're any good, they'll be very helpful. Sometimes you may have to be the MC, in which case the job becomes much harder as you will need to keep working until it's all over. It then becomes important to set up your service team with their own group leaders so you can delegate most of the normal duties to them. When you hire a team, check and double-check that they're bringing the gear they need. In some cases, they may just be providing you bodies or goods and leaving it at that; you may need to source the equipment separately. It can be rented, bought, or even borrowed from your extensive social network. Go through your checklist from napkins to PA systems to extension cords.   Decorations are a huge part of any event. Table linens, flowers, gifts, candles, balloons, banners or backdrops for photography, red carpets, (etc) should always be sourced well in advance. One thing many rookies forget are the finer points of the facilities. Are there enough? Examples are toilets and bathrooms, car parking spaces, wheelchair access ramps, changing rooms, storage rooms and kitchen space, waste disposal bins, wine coolers, power access, etc. These are obstacles that are only workable if you foresee them well in advance.  Also think outside of your event: will transport and accommodation be required for international or out-of-town guests or delegates at hotels, as well as bookings and space made for their transport to get them to and from the event? Understanding the social hierarchy of your event -- if it's not truly yours -- is integral to knowing how to handle any situation. As it is essential that the client has confidence in you, you will need to find out:   Who the key guests are––this is usually straightforward when it is a celebration event––such as the bride and groom. The client is not always the key guest/s but may be part of their group, or not present at all. Who the host guests are––these people often act as hosts at their own tables and tend to be good socializes and motivators of guests. These people are useful to keep a convivial atmosphere and strike up a conversation if things turn quiet, encourage people to dance or to introduce people to other guests to make new friendships. These people should be reliable but are generally useful to know as they will keep you informed, may step in and be a guest speaker or MC for you in an emergency and these are the people overall who make the event flow the smoothest at the front line. Who the peacemakers are. You should be aware at all times who these key people are as you need to advise them of issues and involve them in the handling of issues and disputes where appropriate. This will generally be the head of the family, a caretaker, or head honchos or hired security. Who the decision maker is. For most cases it is yourself as manager, but when you must consult guests and it is not appropriate to involve the key guests (as they typically will be occupied being good hosts), find out who you should consult in an emergency. Ultimately it would be the person who pays the bill if you're charging for your services, or whomever you may deem as "the client" as the person having the final say on the matter.
Send out invitations. Keep track of those who have accepted. Handle what you need to hire out. Find someone who will be the master of ceremonies (MC). Gather your equipment. Cover your bases. Know who you're dealing with.