Grooms have it pretty easy compared to brides when it comes to planning a wedding but there are still several jobs that a groom, by convention, is expected to do. Here's the top four!
Firstly, your bride may spend months finding her perfect dress, so you're expected to dedicate a bit of time to finding your groom's outfit. It's a good idea to look around online before you visit the stores, to have a rough idea in advance of what you are looking for. In the US, traditional attire is a tuxedo. In the UK you'll be expected to wear a morning suit. However, neither rule is hard and fast. Wear what you feel comfortable in. And by the way, just because your bride doesn't show you her dress in advance of the big day doesn't mean you're not expected to consult with her on your outfit!
Secondly, you need to write your groom's speech. There is no easy guide to doing this but the best advice is to keep it short (eight minutes or so is fine) and speak from the heart. If you find writing the speech difficult, put it down for a week or so and then come back to it. It's easier when you're fresh. On the day, have a drink or two beforehand to relax yourself.
Thirdly, you should plan the honeymoon. Although this used to be the sole prerogative of the groom, in reality this has become a joint exercise between bride and groom, for the majority of couples. Speak to your fiancee about where she might want to go - once you've decided, it's down to you to do the planning.
Finally, don't forget to choose your best man. It might be a very easy choice or it might be more difficult, but you can let people down gently by asking them to be groomsmen (US) or ushers (UK). Perhaps they could also give a reading at the ceremony.