Some of the things you need to decide before booking are: How much you are prepared to spend on the cruise. Where you want to cruise. What time of the year you want to go. The type of cruise ship you prefer. The type of cabin you prefer. The kind of things you like to do while cruising. The facilities on board the cruise ship you want to be available. If you like to dress up. What time you want to eat dinner.How you will get to the cruise ship.
Once you have decided where you want to go and which cruise line you want to use, the cabin selection is one of the most important decisions before you book. Cabin selection is normally a function of how much you want to spend. Deck plans for most cruise ships are available in hard copy from the cruise line or travel agent. Usually you can also view the deck plans one line, if not through the search engines then by visiting the official website for the cruise line you have chosen.
The cheapest cabins are normally those mid-ship or on a lower deck. If this is what you want, you will not get a view, but you will get a better ride in rough seas compared to cabins on a higher deck. If you want to be able to look out of your window to see the weather, you should look for an outside cabin with a window or a porthole. Also here you will find that there are many options at different prices.
The most expensive cabins are those with private verandas or balconies. Many of the newer ships feature private verandas or balconies on most cabins, so they are now getting less expensive.
To get to the cruise ship on time for departure and back home again after the cruise is your own responsibility and not part of the cruise package. Therefore your budget for the cruise should include costs for transportation to and from the port of departure and arrival, which is usually the same port. The cruise ship will not wait for you if you are late, so good planning normally involves arriving at the place of departure at least the day before the cruise starts, and therefore also involves spending a night at a hotel.
In many cities the port is quite a distance away from the city itself and from the airport, this is for instance the case for Rome, Athens, Paris and London. By arriving the day before you can get a more relaxed start to your cruise holiday, and maybe you can also do some sightseeing before departure.