Congratulations! You have just learned that you are having a baby. Whether this is your first or not you need to look at cribs. Do you have one already? Is it an antique? A second hand crib whether antique or not needs to be carefully looked at. This is for safety of your new baby.
The screws, bolts, and/or other fasteners should all be in place. Are they loose? Will position of mattress hold under your baby's weight? It is imperative that this be tested before you put your baby in crib. Take something that approximates weight of your baby at about 4 months old. Bounce it off mattress to be certain it will hold its position. If it doesn't it could cause serious injury to your baby or worse.
When setting up nursery (if it isn't already up) consider very carefully where you will place crib. If you place crib near a window and you have Venetian blinds, either shorten cords or anchor them somewhere that your baby can't reach and get a hold of them. If it all possible avoid placing crib near window. As your baby grows into a toddler and s/he attempts to climb out of crib; s/he could possibly fall which could cause serious injury to your baby.
Blankets and your baby are not necessarily a good mix. With incidents of SIDS today, you want to be sure to do everything that could possibly put your infant at risk. It is more advisable to put your baby to bed in a sleeper. If you absolutely have to have a blanket on baby, tuck it tightly around and under foot of mattress with your baby's feet touching footboard. Also you don't want to put blanket any higher on baby than up to his chest as that will help prevent him from slipping under blankets and suffocating.
Bumper pads are a great concept but unless they are secured properly, there is a risk of your baby slipping between mattress and bumpers and possibly suffocating. If you use them they should be anchored in at least eight places one at each corner of crib and at least two spaced evenly on each of sides. There should be a total of 16 ties in all, for top and bottom.
Mobiles are a nice addition and look adorable but... caution here is that if you use a mobile as soon as your baby starts to sit up on his own mobile should be taken down to prevent your baby from getting tangled in it. Also make sure that it has no small removable parts that your baby could choke on. If your crib is second hand no matter whether you had for a previous child or you got it from someone else check out mattress carefully. Make sure there are no cracks or holes in mattress covering. Make sure too that mattress properly fits in crib. Here again, your child could slip between mattress and sidebars or end boards and suffocate. The mattress should fit snugly in crib. Now sheets you use in your baby's crib should also fit properly and not slip and slide. Sheet anchors are available that hook on sheet under mattress and keep it in place.