This is the general shape you are looking for, this is a commonly found but weak conifer psilocybe (spelling? I'm not googling here). I believe this is the correct species, it is commonly mistaken for the liberty cap which is very similar in shape. Either are quite common and basically what you should be looking for though.

I recommend doing some research though, making sure you know specifically what you're looking for and know what similar looking species look like that can be dangerous, such as deathcaps, which although uncommon can be deadly. It's not all that difficult to tell the difference if you've done your research though and very few people make that mistake (or ever find deathcaps).

Research is the key though, in certain areas it pays to know all the various types of hallucinogenic mushroom as some are significantly rarer but quite potent. You never know what you might stumble across. If you're going on a mushroom hunt get a book on it and take it with you, once you start looking you start getting quite good at instinctively knowing the right areas where mushrooms would likely grow, dark damp niches with protection, etc.

Making me want to go hunting for some again now, just to see if they're still growing where I used to pick.

EDIT: A death cap with a noticeably similar shape, take note of the wider and straighter stem and more round and smooth bell shape tip compared to the more conical tip of the psilocybes you're looking for.. Compare multiple images though, mushrooms all grow slightly differently and you can get drastically different looking mushrooms of the same strain.

http://www.naturephoto-cz.com/photos...th-cap-047.jpg