The simple answer is YES.  Even if you intend to plead guilty to the the charges against you, it is very important that you hire and experienced criminal defense attorney.  In many cases, an experienced criminal defense attorney will be able to negotiate plea bargain to a lesser charge or lighter sentence.  If you attempt to represent yourself, you could end up facing much stiffer penalties.  You should ALWAYS invoke your right to legal representation as soon as you have been arrested or even contacted by members of local, state or federal law enforcement.  You should avoid admitting guilt until you have explored all of your legal options.