Good news: Your favorite little black dress can definitely be appropriate for a wedding.
Though black might not be the ideal option for a mid-day spring or summer ceremony, black is perfectly fine for any evening wedding.
Not sure where they're registered for gifts? Wondering about transportation? Need to know if there will be a babysitter at the wedding reception? Don't pick up the phone and immediately call the bride or groom.
Find out if the couple has a wedding website, which could very well include all the information you need.
For a personal touch, pick an item that has some significance for you and the couple, and include a letter that lets them know you put some thought into their wedding gift and got them something they really wanted.
Unless your wedding invitation includes a phrase like "And guest," don't assume you're free to bring a date.
No matter how far you've traveled to attend a wedding, the couple isn't required to pay for your hotel.