Yipes…
You got a Canon Rebel (Nikon doesn’t make the Rebel)…
Is it a Rebel G, Rebel X, Rebel 2000, or Rebel?
You need to use a Circular Polarized (CP) for the autofocus and TTL to work right. If you are using fast film (400-1200) and a flash, then use the CP filter – it will brighten colors and make for gorgeous photos, and remove glare. HOWEVER, the CP filter needs to be rotated to the right spot or it will darken your exposure and may even ruin some shots if you don’t use it right – talk to the people in the photo shop because they can explain to you how to use that filter…
It’s worth it to have the CP filter for sunny days too – it makes a rich deep blue sky and bright, very bright colors…
If you have about $800 laying around, go ahead and get a fisheye lens, the 16mm Canon Ultrasonic is pretty good, and you will have to get it used at 8-9 condition for that price.
You could rent one ($50/week) if you know of some good events happening, and want to play with it…
While you are renting it, take some photos of the interior of your house and your cars – it’ll make the rooms look extremely spacious…
As far as any other filters… well, just take good photos and apply digital effects if you want color changes and stuff… don’t worry about buying too much stuff – just keep shooting great photos!
The CP filter is a must however – for flash and sunlight…
Oh – you might consider getting a 380EX speedlight flash if you don’t have one… it’ll take care of lighting interiors and the automation is very clever on that device… that’ll set you back about $150-200, however…
If you have a Rebel X, it has a built-in Soft focus feature that makes a marvelous soft focus when used with a tripod – it shows “SF” on the feature dial – you must use it with a tripod, though becuse it will shoot two exposures – one in sharp focus, and one out-of-focus, that blend in order to make a soft focus…
The most important part — HAVE FUN TAKING THE PHOTOS!!! – it’ll show in the prints…