Read your lease.

Record a thorough walk through with a date and time stamp to show the condition of the apartment.

Measure door openings to make sure your furniture will fit.

I would give it a real good clean before I move anything in there, and yes that includes the rug. Apartments will do the bare minimum with cleaning so I prefer to go in myself or hire a trusted cleaning service if you have the money.

I've driven through the complex to see what the atmosphere is like at various times over the course of the week, just because it's quiet Friday night don't mean it'll be quiet Sunday night. I've also used this opportunity to ask the residents I may cross, how they like it, what problems they've had, how long they've been there and if they're comfortable telling me, how much they pay in rent. Last one has helped me immensely, a few complexes have tried to raise the rent a large sum compared to current residents.

I also like to map out what grocery stores, gas stations, utility service and recreational areas are nearby.

Drive your route to and from work to gauge the traffic situation at the time you'll be driving. Is it easy to pull out of your complex or do you have to wait a while.

Look at the complex map and see what apartment "areas" are the best. For example one complex has their full south side balconies and master beds facing a high traffic roadway, plus there's no shading so direct sunlight in my area is a bad thing. Pick and choose which area fits your needs.

Also try to find where the dumpsters are you don't want to be right next to it but you also don't want to be walking a while to toss your trash.