The careers service, or people within your chosen industry, can provide you with information about these. You can also look for advertisements in national newspapers on the days that jobs in the area that you are interested in are covered. Most recruitment agencies are paid by the companies for whom they are finding employees, rather than charging the individuals who are on their books. However, it is essential that before you sign up with any agency you check how they operate and what their terms and conditions are. It is probably a good idea to investigate which agency seems best for you before making any decisions.
Small companies tend to be more likely to recruit informally than do larger ones.
As many communications organisations are small this can be a significant problem for people who are trying to get into the sector. For further discussion of the difficulties and suggestions for how to combat them, see The Challenges Presented by the Industries .