1. Through an adviser. You place the instruction to buy with your adviser who then makes the purchase on your behalf.
2. Through a bank or another financial institution. Many bank branches have investment advisers available to help customers, though they may be able to advise only on their own products rather than the whole market.
3. If you are buying units directly you could consider a "fund supermarket" or a "discount broker", which frequently operate through the Internet.
4. By contacting the fund management company directly. Before using this route you should have already decided where you would like to place your money and that you do not require advice.