Do I have to obtain a permit if an electrician does the work?
It depends on the deal you make with the Electrician.  It's common for the Electrician to get the permit, though not unheard of for it to be the homeowners responsibility. The only way to know for sure is to ask the Electrician, or read through the contract/estimate.

It's also typical that if the Electrician pulls the permit, the cost will be passed along to you. You'll likely see it in the estimate/bill, as Permit. You may also notice that the price the Electrician charges, is a bit higher than what the permit office charges. This is because the Electrician will likely bill you for the time they spend dealing with permit issues (filing, waiting in line, etc).