Something that might help point you in the right direction is to check the phrase in google.com first, using quotes. For example, for the first one on your list, if you put quotes on it and check google here is what you will see.
http://www.google.ca/search?num=100&hl=en&q="CroatiaTomorrow"&btnG=Search&meta=
That doesn't look very promising.
The second one in your list doesn't need quotes around it because it's a single word, so the results would be as follows:
http://www.google.ca/search?num=100&hl=en&q=Solitarius&btnG=Search&meta=
Now you can see there's lots more results for you to look thru to see how other people use that word in their web pages. Perhaps one of those web pages will give you an idea of how the word can be used for you to make a web site, or what kind of person might be interested in buying that domain from you to make a website, or it might even help you decide if some people might be typing it in their browser as a .com domain, which would give you some traffic so you could park it to make some money. If you can't think of any use for the word, you still might be able to flip it for a small profit, if it's a word or made up word that has a nice sound to it. It might not be worth your time to try to make a few dollars from it, but if you're just starting out you might want to try to sell it just to get the experience of selling your first domain, even if you only break even.
The google results for the next one on your list is:
http://www.google.ca/search?num=100&hl=en&q="Graphic+Interchange+Format"&btnG=Search&meta=
Then look thru the results to see if you get any ideas on how someone might want to use that domain to make a webpage.
Remember to use quotes around the phrase. If you don't use quotes you will see this:
http://www.google.ca/search?num=100&hl=en&q=Graphic+Interchange+Format&btnG=Search&meta=
That will give you too many results that don't have the phrase you are trying to research.
If you are just starting out, one other thing you could try is to just think up some phrases, then try to guess if you think it is already being used as a domain, then type it in your browser to see if it is being used and how it's being used. For example, take the phrase "red shoes". Do you think that would make a good domain? Well I see it goes to a parking page. Then I checked the whois and it's been registered since 1998.
http://www.whois-search.com/whois/redshoes.com
I guess it must be making money for the person if he's had it for that long. Then I check the google results and it shows
http://www.google.ca/search?num=100&hl=en&q="red+shoes"&btnG=Search&meta=
A quick glance thru the google results seems to show there are people who would like to own that domain and there are probably people who are typing it in their browser. Also if you go here
http://domain-search.domaintools.com/?q=redshoes&de_search=Search&filter=y&bh=A&pool=C&bc=25
it shows you how many other domains are built around that phrase.
Now knowing how good that domain is, maybe you might want to check out other similar phrases, like blue shoes, or red coats, ... stuff like that. I see that greenslacks.com is not taken. There's probably a good reason for that. Anyway, if you do that kind of research for a few months it should help you understand what makes a phrase valuable and you will gain experience and knowledge.
