I have a bunch of ideas for blogs, but I dont want to spend money to get them all domain names. So, im thinking of starting some blogger blogs. However, are you allowed to place amazon affiliate stuff on blogger? Also, are you allowed to place adsense ads wherever you'd want?
Yes, you are allowed to place advertisements on your Blogger blog (whether it's AdSense, Amazon, YPN, Chtika, Clicksor or any other network/affiliate program).
As danielbruzal says you are fine using Adsense, Amazon etc on your blogger blogs. The problem with having all your blogs on blogger is that you have no control over the hosting or account (Blogger could terminate you at anytime without warning). Why not register one domain and create sub-domains for your different blogs, thus minimizing cost. It would also be worth get a cheap hosting package for all your sites. You could still use blogger but have a lot more control.
Personally I don't read blogger blogs as most of them seem to be poor quality made for adsense stuff. Not sure if anybody else feels the same but considering the low cost of domains and hosting you really should get your own site.
I completly agree with mad4. Out of over 20 travel blogs on my RSS reader, only 1 of them is blogspot - unfortunately Blogspot seems to be a haven for spammers, quite ironic, considering Google are trying to get rid of spam from it's search engines, but it helps spammers by offering blogspot free, and Google adsense.