You have all of my sympathy, because a few years back I was in the exact same position as you are (well to be honest, I'm still on the budget). So, with only some point & shoot experience, this is what I did. This might be partially subjective rant, but I think it offers a good beginner perspective when considering the first lens.
After gazillion hours of reading through almost the whole Internet (it felt like it) I decided that 450D was the way to go (note: this was the Q1 of 2009). On the side I came to understanding that the lens is what matters more than just the camera body — and usually the kit lenses are mediocre at best. So getting camera body and lens separately felt like it was the way to go. Reading between the lines, I think you've stumbled into this same conclusion.
Two things at minimum should be answered when searching for the appropriate lens:
- What kind of pictures you want to shoot?
- What is your budget?
So what lenses to consider? I had absolutely no idea. While our soon-to-get puppy was one of the primary reasonings for buying a camera, at the same time I wanted to shoot all the shots mentioned e.g. in What is your favourite photograph? and Which photographer do you find inspirational? questions. I really had no idea what I wanted to do with the camera. Also, with only some P&S background, I had no real experiences on focal lengths and what they would mean in practice — and surely I didn't take e.g. the APS-C crop factor into account. I found myself sighing at the sample shots of different lenses. Like you didn't in your question, I couldn't answer the question #1.1 What I knew was that I didn't want to settle for one style only.
Now, after reading some experiences and technical details on different lenses I was trying to get some grip on what my budget should be. I grouped the lenses into three price-buckets:
- Priced for the pros (e.g. Canon L -line), starting price near 1 k€ (1,3 k$)
- Too cheap, price sub 320 € (430 $); would be good lenses for temporary use ie. replaced with better later on, but the resell price would be disappointing
- Sweet spot for hobbyists, in the middle. Not perfect, but very good and resell price is adequate.
What I wanted was something from the "sweet spot", but the problem was that they would at minimum double my budget. Sadly, I had to go with the cheap.
If I wouldn't wanted the versatileness of different focal lengths (or zoom, as I could'd said) I might've settled to the mentioned 50 mm/1.8. NB Now that I have a 50 mm lens, I can say I would've got disappointed if it would've been my sole starter lens. 50 mm is rather long with 1.6 crop factor and too long for many situations when shooting inside our small apartment.
The two answers so far to my questions:
- I don't know what I want.
- Whatever I want, it is going to rocket my budget — and as a beginner I don't want that, not just yet.
I slept on it and considered I should save money for a good lens; but then again I didn't want this to be a too big of an investment. I also didn't want to wait for another few months.
The sanest conclusion I personally came to was to go with the 18-55 mm kit lens. I read another gazillion articles on it and accepted that while it was mediocre and probably sold at 50 € (68 $) on auction sites, it still is OK for a kit lens. Also buying the kit wasn't too much more expensive than buying just the camera body.
If you're on a tight budget and as beginner as I was, the kit lens is a good introductory lens. While I am an engineering student and like the technical specs and quality over quantity, I think, based on own experiences, it is more important for a beginner to use a versatile lens, which has
- varying focal lengths
- range of aperture options
- autofocus, which can be turned off
- image stabilisation, which can be turned off.
These are good to have, because they teach you how varying one aspect affects the whole picture. Getting to know these features will help you to decide what do you want from your second lens: Do you like the versatileness of varying focal lengths? Do you mostly shoot in 18 or 55 mm? Would you like shallower depth of field in portraits? Can't reach the birds in the sky? Autofocus too slow? Do you want all the same features but just sharper pictures? Etc.
If you don't have any experience, like I didn't, it is hard to even ask what to look for. It is good to keep options open. Kit lens is the safest choice. Go and shoot! Reading reviews only makes you sad (made me).
Bonus: After I got to know my camera and features of the lens, but still on a budget, I bought a couple of old film SLR all-manual lenses and adapters for them. Shame the 450D doesn't have a split-prism viewfinder2, so the manual focusing is a bit tricky.
1) In my opinion, this makes the question perfectly valid in its current form.
2) Well, it can be changed, but then the AF-lights won't blink anymore.