"The Sixth Amendment safeguards to an accused who faces incarceration the right to counsel at all critical stages of the criminal process. The entry of a guilty plea, whether to a misdemeanor or a felony charge, ranks as a 'critical stage' at which the right to counsel adheres. Waiver of the right to counsel, as of constitutional rights in the criminal process generally, must be a 'knowing, intelligent ac[t] done with sufficient awareness of the relevant circumstances.'"
"Beyond affording the defendant the opportunity to consult with counsel prior to entry of a plea and to be assisted by counsel at the plea hearing, must the court, specifically: (1) advise the defendant that 'waiving the assistance of counsel in deciding whether to plead guilty [entails] the risk that a viable defense will be overlooked'; and (2) 'admonis[h]' the defendant 'that by waiving his right to an attorney he will lose the opportunity to obtain an independent opinion on whether, under the facts and applicable law, it is wise to plead guilty'?"
"We hold that neither warning is mandated by the Sixth Amendment. The constitutional requirement [of valid waiver] is satisfied when the trial court informs the accused of the nature of the charges against him, of his right to be counseled regarding his plea, and of the range of allowable punishments attendant upon the entry of a guilty plea."