Congrats on your new horse! Bringing a new one home is always exciting - and maybe just a little nerve-wracking. You want your horse's first experiences with you to be good ones, and that includes her experience moving into a new home. The good news is that horses are very adaptable! Most move into new homes with little, if any, problems. I've moved horses cross-country with no issues at all.
There are a few things you can do to make her transition as smooth as possible. First, find out what her schedule is like in her current home and how she's housed. Try to keep her on a similar schedule and in similar housing at first. For instance, if she's used to being fed grain twice a day and kept in a stall at night, try to do that at home and slowly ease her into a new schedule.
Also find out how she is with other horses. If she's very timid, you might want to put her in with a less dominant horse so she won't get picked on. However if she's a very dominant mare, you might not want to pair her up with an equally dominant horse or a battle could ensue.
Find out what she's used to eating and how much. If you will be switching to a different feed, ask the sellers if you can buy some of their feed to take home with your mare. Then gradually switch her over to your feed. The first few feedings, feed her normal feed. Then replace a quarter of her normal ration with your food and gradually increase the amount of your feed in her ration until she's eating only your feed.
When bringing a new horse home, it is always a good idea to quarantine them from other horses for about two weeks. You can keep her where she can see other horses but cannot touch them. This protects the resident horses from diseases the new horse might bring with her.
After quarantine is over, gradually introduce your mare to her new herd. You can start by putting her in a paddock next to the pasture where she can meet the horses over the fence. Then put her in the paddock with one other horse and once the two of them are getting along, you can introduce her to the herd. Do this after everyone has eaten and when there is plenty of daylight available. Keep an eye on her and make sure she does ok with everyone.
Good luck with your new horse - I'm sure she'll settle in quickly with just a little help from you!The Equine Behaviorist