What to wear
What you need to wear in the woods varies according to the type of wood, the weather and the type of activity you are doing. However there are some basic items which will help you make the most of your visit without ruining your clothes.
Light waterproof jacket
If it's likely to rain on your visit pack a light waterproof jacket to keep you dry. If it's cold outside simply wear lots of layers underneath rather than one thick coat, that way if you get warm you can remove layers.
Old, dark clothing
Woods can be muddy so wear dark and/or old clothes so as not to ruin your favourite items. Try to wear lighter fabrics rather than jeans as lighter fabrics dry more easily if you get caught in a rain shower.
Most woods have uneven surfaces so good, solid footwear with grip on the soles will help keep you steady on your feet. You don't need special expensive walking boots unless you are planning to walk long distances. A good pair of boots or trainers is fine.