Bring some serious SPF! Yes, you can purchase sunblock in Jamaica, but the spf was pretty low and I didn't see any brands I recognized. Plus - it cost way more than it would have back home if you buy it at the resort. I brought some 50 and 75 for me and some 15 and 30 for my husband. Bring a separate one for your face too to avoid breakouts if your skin is sensitive.
Couples Negril is a beautiful, friendly, romantic place. It is definitely rustic and has plenty of island charm. That is exactly what we wanted for our honeymoon so it was perfect for us. The rooms are comfortable but not incredibly fancy (at least not at the entry level, which is what we chose). The staff was amazing - so friendly and helpful. The beach is amazing. I wish I was there right now! There are plenty of cozy places to sit and enjoy the sand and water. The rafts that are part of the beach chairs are really nice and there is plenty for everyone, even with the property at capacity. The food is very good and there is plenty of variety. If you want to be adventurous and try the jamaican food, go for it! We really enjoyed the patties and jerk chicken and calalloo and goat curry! If you venture off the property, the food will be a little more authentic (and spicier) so if you are a foodie, go check it out (like 3 dives chicken) by doing trading spaces and spending the day at CSA and walking off the resort, or taking a cab (inexpensive). Definitely do the catamaran cruise so you can check out the cliffs (magical!) and we really enjoyed snorkeling and the Hobie Cat (my husband is a sailor) too.
Basically, CN is whatever you make it. If you want to be cozy and romantic together, you can have a magical time. If you want to meet new friends and enjoy some fun times at the swim up bar - that's available too! Or have a little of both. Enjoy!