There are many sites that you can check out for leadership seminars. One of the largest is COVEY LEADERSHIP WEEK they have many different activities in the whole week. Along with the seminars, they publish many books and other useful information that can help you boost your leadership skills.
If you don't see yourself as a very dynamic person, you may want to check out THEATRE TECHNIQUES FOR BUSINESS PEOPLE INC. - PEAK DYNAMICS FOR LEADERS . If you don't like public speaking or just have a low self esteem, this may be the seminar for you. Release your potential and become more dynamic!
LEADERSHIP EDGE INC. is dedicated completely to development of practical and effective leadership for life. This approach emphasizes the importance of character, compitence and commitment for long-term leadership that works. This really sounds like a lot of work. But if you just check out A MANAGEMENT SEMINAR FOR TODAY'S LEADERS, you'll find that all of the parts fit together and can take you anywhere you want to go.
If you're looking for a specialist in leadership and organizational development you may want to check out The PACIFIC INSTITUTE - INVESTMENT IN EXCELLENCE (IIE) FOR THE '90'S. Their complete program touches many subjects. Some of them include personal growth, career development, and building a higher self esteem.