These can be an important part of your preparation and something you should consider and plan some time before travelling. They may even be compulsory for some projects. Whether they are or not, hwoever, the important realisation is that you will learn new skills from them, possibly make new like-minded friends and hopefully ahve a great time learning too, knowing that they will benefit you on your volunteer trip abroad.
There are some preparatory courses that you may choose to take or be required to do before travelling. For example if you are intending to teach English as a foreign language as part of your voluntary experience abroad then you should consider taking a TEFL (Teaching English as a Foreign Language) course before you go. These are invaluable and can give you lots of ideas about teaching methods. You may be required to do one of these anyway as part of your agreement with the voluntary organisation who you have signed up to.
There are a variety of TEFL courses of different lengths and which give different qualifications. Ultimately you will decide which is most relevant to you, but a some volunteers even end up teaching English as a foreign language for a living.
i-to-i are an established provider of both online and weekend TEFL courses and their courses are certainly worth looking at, especially if you are considering undertaking a volunteer placement with them.
Language courses too may appeal to you and as described in our languages guide learning the native langauge of any country you are visiting before you travel can be of enormous benefit to you. How you choose to learn the language depends on what suits you of course and the time you have, whether it is an online course, a CD or DVD based course or an evening class.
Do be aware that,depending on the experience you have chosen, you may be required to take other types of preparatory course, be it practical or a general one to preare you for what is ahead. you should be advised of such courses by the organisation you are doing the volunteer project with.