Since you do not tell me what kind of fern that you have, I will be giving you a few articles that I hope may be of help you.

To answer your specific questions:

When should I put it back outside? While it is tempting to put the fern outdoors as soon as the temperatures say “Spring”, since it has been indoors all winter it will need time to acclimate. Be prepared to cover it especially in evenings, or if the temperature dips down. The fern will also need time to acclimate to sunlight, since it’s been the dark for so long. I would suggest starting by placing it in a partly-sunny spot for a few hours, and increasing its sun exposure over time.

Should I remove what appears to be dead fronds (or do I cut it all back)? Be slow to remove what appears to be dead; give it time to acclimate, and you should be able to tell if it needs some dead fronds pruned off. Do not stress about a plant that is alive but looking ragged -- so long as the plant survives, it should restore itself to its former glory when it is moved back outside.

When should I begin watering it? Provide enough water to keep the soil damp but never allow it to get wet or soggy. Mist tropical ferns need humidity every few days to keep the plant from drying out. Since you likely withheld fertilizer during the winter, considering resuming monthly feeding with an all-purpose, water soluble fertilizer.

That said, since you mention that you did not water it over the winter, consider carefully how to re-hydrate it. Typically, although the plant was effectively dormant for the winter season, it would have needed watering once a month, just enough to keep it moist. it is now very dry, so will be thirsty -- do not over water.

I hope your fern resumes happiness on your front porch.