By Andrew SternCHICAGO (Reuters) - Former President Bill Clinton (news - web sites) launched his book tour on Thursday, describing his soon-to-be published memoir as being tough on himself rather than on his enemies. Reuters Photo "My Life" is scheduled to arrive in bookstores on June 22 with an expected price tag of $35 for its nearly 1,000 pages. "A lot of presidential memoirs, they say, are dull and self-serving," the two-term president told a booksellers convention. "I hope mine is interesting and self-serving. But I don't try to settle a lot of scores here. I don't spare myself...