Penguin good first post, as you've asked the things that probably most just or soon-to-be pregnant people think!
I haven't found a definitive book of actual facts out there that answers your questions, but I did do a lot of internet research, and made my own decisions about the risks.
It is of course all a matter of your own personal judgement of risk versus benefit, and any deeper understanding you can glean about the actual science behind things.
I think for me, it split into broadly two areas: the things that affect the foetus every time you have/do them. By this I mean things like alcohol, caffeine, hot baths, excess of mercury high oily fish i.e. every time you indulge (or more accurately over-indulge), the baby might 'feel the effect' so to speak. Also in this category for me is pate, as apart from the listeria risk (which is in my second category below), it is also high in vitamin A which has been associated with early miscarriage.
The second area is things that are more theoretical risks, that is, there is hardly any evidence that babies are directly harmed by these things under normal circumstances. For me this included a lot of the food concerns, in that the risk is only there is the food does actually carry listeria or salmonella or whatever. So for me, eggs for example were not contraband, as hen's eggs in the UK are now all vaccinated for salmonella so the risk is more miniscule than miniscule. Ditto for a lot of food concerns, e.g. prawns, if fresh frozen, defrosted yourself in the fridge and eaten immediately, the risk is tiny, and brie, if bought fresh and well packaged from a supermarket and kept in the fridge and eaten while fresh, the risk is again tiny. I have been a lot more cautious about things like cold meats, cheeses, fish etc. that has been hanging around on buffet tables, and in sandwich bars where you just don't know how it is kept.
So that's been my approach, avoid things that are a definite risk, and be very choosy about things that are a theoretical risk, to try and minimise the chances of them being an actual risk.
Everybody has a different approach though and I would never criticise anybody for being more or less cautious than I. I think I probably fall into the 'less risk averse than average' category, but with all of my decisions, I have found the more research into actual facts that I have done, the more reassured I have felt.
So I guess my advice is, do some reading and research, and then it's really up to you to make your own decisions!
Good luck with TTC!
D