The Thank You. Next, it's always a good idea to thank your employer for the opportunity, describing some of the key things you've enjoyed and learned on the job. And yes, this is true even if you're thrilled to be leaving. Remember__you may need these people for a reference down the line, and leaving things on a good note will leave a lasting (positive) impression.
These are vague... are you available to train a replacement anytime, even after your last day? Are you saying you'll be too busy to help prepare someone else or that you'll be busy helping with the transition? As with everything else in your resignation letter, clear and concise are the way to go.