Hi I was wonder if I post images or videos on my blog from search engines or free sites and I credit the photo's and show links, can I get into any kind of trouble? Thanks -byount-
Are you using them for profit in anyway? If so, no - you can't do that. If you're just using them to illustrate a blog entry or whatever, yes - you can do that.
Unless the video or image is expressly licenced for use free of charge, like the Wikimedia Commons licence granted by Wikipedia on their content or like Copyleft, then no, you can't and shouldn't use it without contacting the copyright owner for permission. Any use of copyrighted material without the copyright owner's permission is an infringement of their copyright. Just giving credit is generally not sufficient to absolve you of the offence.
I'm quoting US Copyright Laws in regards to the Fair Use clauses. I'm assuming OP meant the US, which totally allows the usage of copyrighted things under certain conditions. http://www.bitlaw.com/copyright/fair_use.html