Hey yonames,
I am pretty new to this domain stuff too, so I know how you feel. Can be a bit overwhelming at times.
First I would like to mention that if you are looking for great domain names, you're best bet is to look for expiring and deleting domains. Chances are if there are any good domains out there, they are probably already taken.
But none the less, here are my suggestions:
For hand regging I like to use a couple different tools. One is to get a couple keyword ideas off the top of your head and type them into Google's adword keyword tool. If you have the synonyms box checked then it will spit out some relevant keywords that correspond to your existing ones. You can pretty much go at this all day.
Another good tool with alot of different options is makewords.com they have a handful of various ways to find unregged domains, plus it will tell you whether or not it is available with the results.
One more interesting site I just found is availabledomainnames.com they have lists of available domain names that you can look through to see if there are any you fancy.
As far as finding expiring/deleting domains, I suggest heavily on going to snapnames.com and going to there "auction list" page. There you can find lists for expiring domains for the next five days. Look through those names and compile a list that you think might be worth something. Then I would suggest going to the adword keyword tool again and typing in those names to see how many people have been searching for those keywords. Just make sure that you have selected "exact" search instead of "broad" That's a mistake I made and it makes a big difference on finding the value of a domain.
I hope this was helpful
Good luck and have fun!