If he is arraigned, then he is charged. Does not seem like he has been charged with anything at this point. If he is asked to enter a plea at this court date, then he is being arraigned.
In most places, until the state formally charges someone, there is no entitlement to a PD. If he is asked to make a plea, he should plead not guilty and ask for a PD.
Insofar as the question of going to jail is concerned, I would plan on having to post some bail. If he is released without the need for bail, so much the better. But, if you plan for the possibility of posting bail, you can make some calls and figure out how much you might need and what the process would be.
The bail amount is determined by the court. Many people deal with a bail bondsman for these issues. Most bail bondsmen are located in or near a court house. Essentially, you buy a bond from the bail bondsman that guarentees his appearance at future court dates. If he does not show up, then the bail bondsman has to pay the entire bail to the court (and will likely come looking for him.). The fee for the bail bond likely will not be refunded even if your husband is later exonerated or the state drops the charges.
In some jurisdiction, you do not have to use a bail bondsman. So, inquire carefully about what might be required where you are.