Miles played for the Jefferson Democrats in Northeast Portland. The Democrats won the 2000 4A Oregon state championship, beating Tualatin 58-44, and capping a 28-0 season. The Democrats finished the year with a No. 4 national ranking and several other players went on to play in college, such as Michael Lee (Kansas), Thomas Gardner (Missouri), and Brandon Brooks (USC).
After being named the Oregon 4A High School basketball player of the year in the state of Oregon as well as McDonald's Morgan Wooten National Player of the Year, Miles attended the University of Kansas, where he starred at the point guard position for the Kansas Jayhawks men's basketball team. He helped lead the Jayhawks to two consecutive Final Four appearances in 2002 and 2003 and an appearance in the 2003 national championship game. He is the all-time assists leader (with 954 career assists) of both Kansas and the Big 12 Conference. He was named to the All-Big 12 Team in both 2004 and 2005.
He was also named to the All-Big 12 Defensive Team 3 times and he finished his college career in 8th place in NCAA history in assists and also in 2nd place all time in Kansas history in steals.
Miles signed in September 2005, as an undrafted rookie free agent with the NBA's Golden State Warriors for the 2005-06 season, but was released in January 2006, before his contract became guaranteed. He played for the Fort Worth Flyers in the NBA Development League for the remainder of that season. There, he teamed with his Kansas class of 2005 teammate Keith Langford.
He signed for the 2006–07 season with the French League club Élan Béarnais Pau-Orthez, a team that played in the Euroleague that season and with PAU he won the French National Cup championship that year. He played with the Spanish ACB club Cajasol Sevilla in the 2007–08 season.
In August 2008, Miles joined one of the three Euroleague teams from the Greek League for the 2008–09 season, Panionios. In October 2009, he signed with another Greek team Aris BC for the 2009–10 season.
In 2010, Miles joined the try-outs for the Warriors, but was released days before the start of the season. He signed with the Reno Bighorns. He was sent to the Bakersfield Jam, but was quickly waived due to injury.
Miles returned to Europe in August 2011, when he signed with BC Krasnye Krylya. In 2012 and 2013, he won the Russian Cup with Krasnye, in the second he was named Finals MVP. With the team he also won the 2012–13 FIBA EuroChallenge. In July 2014, he left Krasnye Krylya.
On July 9, 2014, Miles signed a one-year deal with Lokomotiv Kuban.
Following his career as a player, Miles was hired at the University of Kansas as assistant director of student-athlete development for the 2015-16 season. The following year, he accepted a position as assistant coach at Florida Gulf Coast University under head coach Joe Dooley, a former coach of Miles's at Kansas.
On August 10,2017 Miles was named head coach of the Santa Cruz Warriors.