Just west of this city, the Flatirons are likely Boulder's most popular rock climbing destination. If you're a seasoned pro, you'll find a number of challenges here. Check out this link to get a feel for what the Flatirons have to offer: www.mountainproject.com/v/colorado/boulder/flatirons/105797700
For those looking for a guided climb or a lesson, there are number of outfitters in Boulder. One of them is run by Bob Culp, an American Mountain Guides Association certified guide. His climbing school has been around since 1969 and offers rock climbing lessons year-round.
Private lessons, group lessons and guided climbs are all options. The school will provide all the gear; you just need good shoes, and comfortable, loose-fitting clothing appropriate for the season...and a sense of adventure!