First, let's take a look at your camera gear. If you've got a three-year old entry-level APS-C or Four-Thirds digital SLR, a couple of kit lenses, a decent flashgun and a good solid tripod then you're well equipped for most types of hobby photography, but you're not even close to the sort of gear you need to shoot a wedding properly. Churches are generally not well lit, and many prohibit the use of flash during the marriage ceremony, so you're going to need a camera that can focus quickly, accurately and totally reliably in low light and produce high quality noise-free images at 1600 ISO or higher. While there are a few high-end APS-C cameras that can perform at this level, for the best results most wedding photographers will use a compact full-frame DSLR, such as a the Nikon D700, the Sony A900, or the Canon EOS 5D MkII. The larger full-frame cameras such as the Nikon D3x and Canon EOS-1Ds MkIII would also be a good choice for quality, but they're very heavy and would be tiring to use for a whole day. I recently shot a friend's wedding using a Canon EOS 5D Mk II as the main camera, with my old Sony Alpha A100 as a backup, and it performed brilliantly.
To help capture sharp photos in low light you'll also need some fast lenses, preferably f/2.8, but at least f/4, and image stabilisation is absolutely essential, whether it's optical lens stabilisation or the sensor-shift system used by Sony. As for focal length you'll certainly need a good wide-angle lens to capture interior shots and large groups of people, but you'll also need a short telephoto for close-in shots during the ceremony. Some photographers will use a selection of fast prime lenses, for instance 28mm, 50mm and 100mm. Personally I prefer to use a 28-105mm f/4 wide-zoom lens as a main lens, with an f/2 135mm prime lens as a backup.
A good flashgun is also essential, mostly for fill-in flash on the formal portrait shots, but also for later at the reception. You need to have one that has a dedicated connection to your camera, so it can use the TTL metering to automatically balance with the ambient light to provide fill-in. The latest modern Speedlite-type flashguns such as Canon's excellent 580EX II are ideal, since they have tilting and swivelling heads, very fast recharge times and enough power to fill a large room.
You'll also need a good solid tripod with a quick-release plate, a large Lastolite-type portable reflector, and enough memory cards and spare batteries (for both camera and flash) to last the entire day. You should be shooting entirely in Raw mode for maximum quality, and for a full-scale wedding and reception you can quite easily find yourself taking anything over 300 shots, so make sure you've got plenty of storage capacity available for the whole day.
If you are planning on doing the prints yourself, your old £30 inkjet just isn't going to be able to produce the kind of quality and quantity you'll need. You really need a top-of-the-range photo quality printer, such as the Epson R2400 or Canon PIXMA Pro9000 Mk II. They're expensive to buy and not cheap to run either, but being able to offer A3 prints is a big advantage. Alternatively you'll need to look into local photo printing services. Again, not cheap, but at least the quality should be guaranteed.