Im new in the ways of Wicca and i was wondering, since the rede says do no harm, does smoking count as doing harm?

Merry Meet Seeker,
What a wonderful question! I can see that you are looking through all your actions to determine what is harmful and what is not. The Wiccan Rede goes very deep, doesn’t it? On the surface, many things we do seem to affect no one but when we dig deeper and deeper, we are amazed at how much harm we may do to others, the environment or even to ourselves.
Smoking is slow suicide. Many of us got into that habit because our parents were doing it, our friends did it or it was in vogue. Movies, dramas and even in offices and movie theaters, smoking was considered “haute” or “hot”. Hot it really was, because it hurts (cooks) our body. If there are people who depend on us, such as parents, spouse, children, grand-children, neighbors, etc., they are all hurt by our actions.
It is not just that you may hurt yourself, sometimes our children also watch us and learn to do things in a manner that is similar to what we do. In other words, you can’t say “Do as I say, not as I do”. Smoking affects the health of even unborn children in the vicinity or where you walk or work.
Even if you are not concerned with children or family, as a Wiccan you are expected to be a good citizen. This means taking care of yourself, physically, emotionally and spiritually. Addictions make us weak. To make your mind stronger, and to make your spells work, your aura should be perfect.
Think deeply as to why you smoke and find ways to quit from that addiction. If you are successful, you will see your magickal talents multiply and bloom.There are many spells that will help your spirit get rid of addictiions. Use them willingly.
Brightest Blessings.