Once you have decided to commit to the sport of windsurfing, there are many choices to make in acquiring equipment. The variety is bewildering, and it becomes obvious very soon that it can easily blow through even a generous budget. At this critical phase a little advice from those who have faced the same issues can be very helpful. There is a sane passage through!. I personally have made my own mistakes and have wasted my share of money. I am much wiser now. My recommendations are:
Go ahead and get a full wetsuit, but get it at a surf or windsurfing shop, not through mail order, so you can try it on. Good fit is essential to comfort and warmth. You can use it for other water sports too, like surfing, snorkeling and kayaking, etc.
Sign up and take a couple of weekend lessons through a reputable windsurfing shop. These will cost around 50-70$ each but are a good investment. The Water Planet shop, located just behind the credit union on Bolsa off of Springdale is one such shop. Captain Kirk’s in San Pedro is another. If you've sailed any kind of sailboat previously, that helps a lot.
In terms of equipment, the two things that really matter (where quality considerations are really important) are the mast and the sail. The rest can be bought with economy in mind, including used.
Get a two-piece carbon slalom mast 460 cm long, MCS 25 stiffness, constant curve flex pattern. This will cost about $200 or more, but is way better than a fiberglass or aluminum mast. It's a piece of equipment you will take with you as you progress, and is an excellent investment. If you weigh less than 120 lbs, a 430 cm mast is probably even better. Wave masts are more durable, but the excess weight easily outweighs the extra durability, which is unnecessary at this stage. A good carbon slalom mast will last many years. This is my top recommendation!
After taking lessons, talk to other sailors, say at a club meeting or at the beach. Find out what sail size an advanced sailor of your size and weight tends to use most frequently. I weight about 150# and use a 6.0 sq-m sail almost always locally. If you weigh more you will need a larger sail. I could probably use a 6.5 as well, but big sails can be hard to handle and cumbersome. Sail size goes down for really experienced (read: efficient) sailors, and significantly as weight goes below 130 lbs. With a large, lightweight board one can get away with a smaller sail. If possible, get a sail with 1 to 3 camber inducers. This type of sail is reasonably easy to rig, and delivers peak performance over a broad range of wind speeds. Just commit the money, and get a new one, or one that's slightly used. Make sure of mast compatibility. Some earlier sails, and some North sails were designed for another (flextop) mast flex pattern, which is now obsolete. All the manufacturers have gone to Constant Curve in the last few years. Now you’re ready to consider the boom.
When buying a boom, make sure its length range is appropriate to the sail size you intend to use. The new booms are very good. They're easy to rig and tolerant of sand. Aluminum is fine. Carbon only yields a slight weight advantage, but at a horrible cost.
You'll need an uphaul line. The ones with a bungee inside are very convenient, and get out of the way when you're sailing.
The mast base and extension are also important. Get a long extension, so you can later use bigger sails if you need to. Make sure it fits fairly snugly inside your mast, but leaves room for possible sand fouling. You may be surprised at how much extension will be sticking out of the bottom of your mast with your largest sail. These usually have integral sheaves (pulleys) for either 4:1 or 6:1 purchase. An "easy-rig" (a little plastic or metal gripper for the small downhaul line) is also nice, and saves wear and tear (not to mention pain) on the hands. Also a mast base pad is nice for protecting your deck and toes. Get advice on how to rig the sail. My advice is to tighten the downhaul until all the wrinkles just disappear, then cleat it. On cambered sails, outhaul is easily set afterwards. Play with it on your lawn.
All of the above should work with your first board, and successive boards as you improve. In other words, it stays with you and is a great investment. The general trend is to start with a long board, (like 12', with daggerboard) which I recommend buying used, as cheap as I could get, and then to move to successively smaller boards as your skills improve. Move to a large slalom board as soon as you can handle the longboard in enough wind to make it plane. It is essential that the slalom board have enough volume that you can easily uphaul it without one end or the other sinking. A minimum of 110 to 130 liters is a good rule of thumb You will be surprised at how much faster a board without a centerboard slot can go!
Until you're fairly advanced, the length and flotation of the board is way more important than its shape, so go cheap. But don’t buy a board that weighs more than about 25 lbs. Excessively heavy boards do not plane well.
If your new board didn’t come with a fin, get as large a fin with as little sweepback as possible. Often a dealer will have a "bargain box" full of fins and other goodies that didn’t sell well. This is not a bad place to look for your first slalom fin. Beware that there are several fin base systems out there - so make sure you know what kind your board has. Take your board along and try different fins out if you need to. The length of the fin is important, too. For an average sized person a 12" to 14" long fin is adequate. Generally if you are a large or heavy person and have a wide board, a longer fin is appropriate. There is a fair amount of mythology out there on the subject of fins, so stick to basics: size (planform area) and low sweep.
Good luck, and I hope to see you out there!