Outdoor guides lead groups of people on activity sessions; they normally focus on their own specific areas of interest such as fishing, hiking, photography, bird watching or nature expeditions.
Work is normally undertaken in a self-employed capacity by advertising locally or through travel agents. Some local authorities, charities and conservation bodies - such as the RSPB - do employ people.
The job of the guide is to suggest any specialist equipment that may be required, locate suitable locations to carry out activities and follow good conservation practice. You would also be responsible for the health and safety of the group and provide any first aid if any accidents were to happen.