Read the ads in the local papers, such as the Dunoon Standard and the Oban Times
Put an advertisement in yourself, saying you are looking for accommodation
Contact the local solicitors, accommodation agencies and estate agents
Look out for small ads that appear, for example, on the supermarket notice boards or in the windows of some shops and post offices
Ask around, particularly in rural areas where some private renting opportunities may be "advertised" by word of mouth.
Local tourism offices may have details of some holiday lets and their owners, who could be contacted to explore the possibility of winter or longer term lets. There may be a charge for the published list of accommodation.
In some rural areas, local estate offices may have details of houses to let on their estates.