I saw your forum and felt both sympathy and a little fear. While I understand other photographers' frustrations, it sounds like you are genuine in your attempts. You're admitting you're in over your head and are now trying your best to learn! That's a start.
First of all don't be shy about informing the couple again that you have no experience. If they really are okay with that and truly don't want to spend the money on an experienced pro, then that's there decision. But make sure it is crystal clear. I don't know how well you know this couple but a lot of people want something for nothing. They expect top notch quality but aren't willing to pay for it. If that's the case, run don't walk away from this as fast as you can. When I started out in weddings, I tended to under charge and that was a big mistake. The worst clients were the ones who wanted to pay the least. They expected the most.
Secondly lighting is only one issue. But yes to having an external flash like the SB 900 or the cheaper 600. In smaller areas with lower ceilings, tip the flash upward and let the light bounce. It creates a nice soft effect. However in large churches and big buildings, the darkness can be an issue. It sounds like you are able to practice ahead of time so buy that flash and practice with it. I am a big advocate of bouncing the flash as opposed to straight on. You will see the difference. Practice first on some friends.
Third...Weddings are a strange mix of hurrying and waiting. You will feel like you need to be in ten places all at once. Know really well the order in which everything is happening, how long the ceremony will be, any rules or restrictions on flash photography etc. Know when things are about to happen like the kiss...exchange of rings, etc. Those things only happen once and you really need to be read for them (hope your couple likes a long kiss). It's not the end of the world if you miss some little things...but you want to capture the important moments. This feeling of waiting for things to happen will continue throughout the event but during the reception make an effort to look for pictures. Look for that little girl twirling in her dress or some guest laughing or another guest looking at the bride's rings. Take detail pictures of flowers, dresses, shoes, table settings! Take a zillion pictures! You can always delete later.
Understand depth of field and wide vs narrow depth of field. For portrait shots of just the bride for example or maybe just her flowers you want less in focus (wider aperture)...I can explain this if you want...in a different place than this forum. Make sure when you take posed pictures that you take many (people blink). Make sure everyone is standing close together...space in between people looks weird. Make sure everyone is looking at you (eyes always wander to other cameras or background distractions). Watch little details like if one guy has his jacket open or another guy has it closed (think uniformity).
Do you know how to use photoshop? I know that things like white balance and the technical sides seem important. Believe me they are...and if you were a pro charging $3000 you better know that stuff inside and out. But if these people are willing to hire someone inexperienced with amateur equipment then focus more on getting the moments with nice clear, focused images. White balance can be fixed in photoshop to an extent. The D3000 is not great in low light and has a lot of noise at anything over 400 ISO so I'd be careful of taking shots without flash or in low light. Like I said, try your best to practice technique and learn more...but in the moment when that bride walks down the aisle and your hands are shaking and palms are sweaty, all that knowledge might go right out the window.
Feel free to send me more questions...happy to help.
First of all don't be shy about informing the couple again that you have no experience. If they really are okay with that and truly don't want to spend the money on an experienced pro, then that's there decision. But make sure it is crystal clear. I don't know how well you know this couple but a lot of people want something for nothing. They expect top notch quality but aren't willing to pay for it. If that's the case, run don't walk away from this as fast as you can. When I started out in weddings, I tended to under charge and that was a big mistake. The worst clients were the ones who wanted to pay the least. They expected the most.
Secondly lighting is only one issue. But yes to having an external flash like the SB 900 or the cheaper 600. In smaller areas with lower ceilings, tip the flash upward and let the light bounce. It creates a nice soft effect. However in large churches and big buildings, the darkness can be an issue. It sounds like you are able to practice ahead of time so buy that flash and practice with it. I am a big advocate of bouncing the flash as opposed to straight on. You will see the difference. Practice first on some friends.
Third...Weddings are a strange mix of hurrying and waiting. You will feel like you need to be in ten places all at once. Know really well the order in which everything is happening, how long the ceremony will be, any rules or restrictions on flash photography etc. Know when things are about to happen like the kiss...exchange of rings, etc. Those things only happen once and you really need to be read for them (hope your couple likes a long kiss). It's not the end of the world if you miss some little things...but you want to capture the important moments. This feeling of waiting for things to happen will continue throughout the event but during the reception make an effort to look for pictures. Look for that little girl twirling in her dress or some guest laughing or another guest looking at the bride's rings. Take detail pictures of flowers, dresses, shoes, table settings! Take a zillion pictures! You can always delete later.
Understand depth of field and wide vs narrow depth of field. For portrait shots of just the bride for example or maybe just her flowers you want less in focus (wider aperture)...I can explain this if you want...in a different place than this forum. Make sure when you take posed pictures that you take many (people blink). Make sure everyone is standing close together...space in between people looks weird. Make sure everyone is looking at you (eyes always wander to other cameras or background distractions). Watch little details like if one guy has his jacket open or another guy has it closed (think uniformity).
Do you know how to use photoshop? I know that things like white balance and the technical sides seem important. Believe me they are...and if you were a pro charging $3000 you better know that stuff inside and out. But if these people are willing to hire someone inexperienced with amateur equipment then focus more on getting the moments with nice clear, focused images. White balance can be fixed in photoshop to an extent. The D3000 is not great in low light and has a lot of noise at anything over 400 ISO so I'd be careful of taking shots without flash or in low light. Like I said, try your best to practice technique and learn more...but in the moment when that bride walks down the aisle and your hands are shaking and palms are sweaty, all that knowledge might go right out the window.
Feel free to send me more questions...happy to help.
:greenpbl: 
Touche! :lmao:
