Last year when I decided to take up Triathlon I had a massive problem whereby I not only had to concentrate on the training strategy, fitting the training in around my current lifestyle but I needed the right equipment and Triathlon gear. I started spending lots of time on websites that supposed to deliver only the best gear which would make me a champion without doing any training. I can guarantee you that the opposite is true. No matter what equipment you have, you will need to train and none of the equipment will help if you haven't practiced. 

Budget

Everybody has a different budget and therefore can purchase different type of materials. I would say no matter what your budget is, if you are a beginner then do not go for the high-end gear. Oh yes, it would be very easy to spend £5000 on a bike, but where is this going to take you? You are going to gain maybe, if you are lucky, a few minutes, in the grand scheme of a Sprint Triathlon lasting 90 minutes, this isn't worth it. However for some type of equipment, which protect your body I can only advise to get the best. Here is my overview of "must have" equipment and the "probably should have" equipment. You will need to allocate about £700/£800 for the total equipment. 

First priority list - Must haves

Running shoes: Without a shadow of doubt this is the most important equipment you must buy. I had my fair share of injuries and I can blame partly my running shoes for these injuries. Don't go to a wholesale sport shop and get the one that are looking great and are expensive, this is clearly the wrong approach. Go to a specialized running shop, make sure they take a video of you running on a treadmill, analyze the video and based upon this they should give you proper recommendation for the right pair of shoes. Initially I was very skeptic against this practice as the shop always wants to sell you any show, no matter what. Till so far I cannot complain and have been well off, this remind me that I need a new pair as you should change your running shoes after about 300 miles. 

A bicycle: Without a bike you would not be able to compete and you would not be able to train so logically this is in my list of "Must have". Some websites mention that it is all fine to use any type of bike. I don't believe in this, even if you are a beginner. I was riding my mountain bike for a long time and only afterwards looking at it I noticed clearly the difference in speed and aerodynamics. When I bought my road cycling bike I was doing on average 14 mph on my mountain bike, from the moment I started riding my road cycling bike an average of 17+ mph was very common. I can recommend to get a road cycling bike, but don't go mad on it, there are many different styles and makes. If you are purely a beginner you should be able to find something for about £400. I have completed now 3 triathlons and have not witnessed any form of jealously or envy. No matter what bike you have you are welcome in any competition. It is worthwhile considering having your bike fitted properly. This would be a one off cost and they will set the stem, saddle, handle-bars, etc. based upon your height, this could save you some considerable time and possible injuries. 

A heart rate monitor: I personally cannot live without my Garmin, see also one of my previous posts. I need to have something that I can use as a benchmark how well I've done, something that measures my workouts. I just love figures and keep track of my history and can see my progress over time, I closely watch my heart rate, so to avoid overtraining. This is more of a personal choice and some people cannot stand using this type of device. 

Bicycle shorts: I advise you getting a cheap pair, which you can use, on the bike. After 20 miles on the bike you will welcome some additional padding on your behind. These are very cheap. 

Goggles: Without one you will get easily annoyed by all the water, using one in the pool gets rid of all the chlorine inside your eyes. I have a second pair, which has bigger glasses, and I use this one only during open water swims and races.

Second priority list

Cleats and biking shoes: Not strictly a must have have but something that could help you in your performance over time. There will be a time gain by using cleats on your bike. Most of the road cycling bikes come with cleats pre-installed. If you have cleats you need a pair of biking shoes. This was a tricky purchase for me, I ended up buying the first pair I noticed in the same shop as I bought my bike from. This turned out a mistake and I probably need to purchase a new pair for next season. I might have a pair which are not the right size and are very hard, which isn't practical during transition. 

Tri-Suit: If you don't want to mess around with changing clothes in between transitions then you better get yourself a tri-suit which quickly absorbs the water and is quickly dry. I bought myself a Tri-Suit from the moment I had decided that I was going ahead with my first Triathlon, I cannot see the need to purchase anything sooner. All the training, running and biking can be done in normal shorts and t-shirts. 

Sunglasses: Strictly speaking this is not necessary to start competing in your first Triathlon but I can recommend having a set for on the bike, you want to protect your eyes from insects flying in during a bike ride and from any sun. I don't wear glasses when I'm running, I found that most of the times they are just hopping on my nose.