seaking,
Port Harcourt at present is a bit unstable, but not as bad as some would have you believe. You don't say what you're coming to do or who you're going to be working for. I would not wish to compromise any company security precautions on a public forum, but if you PM me, I'll let you know some more.
If you're coming out to fly helicopters, have a good read through the 'What's New in West Africa' thread on the Rororheads forum as this will give you a lot of the information you're after.
If you're coming to work for either CHC or Bristow, they'll arrange your flights to Port Harcourt NAF Base with either Aero or Arik, both of who have secure passenger terminals on the military base. They'll also meet you and provide you with transport with an armed police escort as neither company allows unescorted transport these days. Both companies have housing in secure areas with armed guards and armed escorts to and from work. Both companies also have overnight curfews for all expatriate staff.
I would not describe kidnappings as commonplace - that's a bit of an exaggeration - but they certainly are very much a possibility in the present situation and certain militant groups have threatened an increase in kidnappings. This may be an idle threat or not, but it's certainly having the effect in creating something of a climate of fear in Port Harcourt and causing a number of expatriates to either leave or send their families home for now. Surprisingly few expats here catch malaria, but it's definitely worth taking precautions against getting bitten. Most oil companies require their staff or contractors to take some kind of anti-malarial prophylaxis; usually doxycycline or malarone. I'd also suggest that you carry co-artem with you in case you do catch malaria. Some of the companies will issue you with this anyway.
At the moment, I'd recommend that you don't go out at night as there have been kidnappings from some popular expat nightspots in Port harcourt. I'd scarcely describe the Novotel as either 5 star or well fortified, but it's not too bad (about European 3 star) and has some security. It's also just across the road from the NAF Base which gives it some extra security. There are a number of reasonable hotels in town, close to the NAF Base, but if you're with a company, they'll sort out your accommodation, as most major companies now have professional security advisors from companies like CRI or Armor Group who give their advice as to which hotels are safe.