My biggest piece of advice is to get paid in advance and ensure you don't have to pay out yourself personally as it can be a long wait to get re-imbursed.
Get a decent rotation, especially if on the GLEX.
There are plenty of corporate aircraft out there and plenty of crews. I think most people last about 2 years, some shorter and some haven't/wont leave. Also, there are plenty of ex-pats out there and you'll pick up their 'local' advice.
The basic infrastructure isn't there. Don't expect anything and you wont be disappointed.
Most of the aircraft aren't on the Nigerian register and the owners like to send their aircraft to the big MRO's so most aircraft are well looked after.
If the terrorists continue or even attack ex-pats then a lot of ex-pats will leave. The aircraft owners will have to significantly increase their pay to retain some of their crews.
PM if you have any specific questions.