Cybergray,
Will Hill is a good one, same software as Intercasion, Sands of the Caribbean, Peach Casino, and a few others. They seem to have the cheapest monthly bonus, only $40/40pounds per month match. Intercasino does $80/month typically (sometimes they increase or decrease this) and wagering requirements are reasonable. My favorite game in this software is Let it Ride. I've hit at least 3 4 of a kind, and one straight flush on it over the years I've played it at intercasino, etc. The straight flush just happened last month at Peach Casino, that was sweet! Wish I'd bet the bonus buck before the hand though :-(
Stay away from RTG software based casinos, they have become nothing but problems lately and definately not a place for a newbie to cut his teeth. Stick to Microgaming, Playtech, and Cryptologic based casinos until you have more experience.
Also, be SURE you read every single word of the terms and conditions posted on the website and in any email offers you receive. Double check these terms with the casino BEFORE you play one cent of real money so that you completely understand what is required of you. If you don't like or understand the terms, tell them to take back the bonus money before you play even a single hand/game. Once you start playing with bonus money, you are committed to those terms & conditions and for the most part you can't cashout until you meet those terms.
Also, get yourself a little notebook and keep a record of your deposits, play & withdrawls, especially when there are bonuses involved. When you ask a casino for clarification on something, I suggest you do so by email rather than phone so you have it in writing if there's a dispute. Print out and/or copy the terms & conditions page to your hard drive if you accept a bonus.
Neteller is a good payment method. Its fast & reliable for both depositing & withdrawing money. I personally don't like Firepay and don't recommend it. When you go to withdraw money from a casino, they will usually ask for some identification (usually a license/passport and a utility bill, etc). You should scan in these items and have them on your hard drive so you can send them in as soon as they are requested. That will speed up yor payouts. Make sure you always use accurate information (birthdate, address, etc) when you sign up, or you'll have problems when you cashout.
Also, I'd suggest setting up an email address specifically for your casino & neteller activities. That way, when the spam starts coming (and it will), it won't be coming to your regular email address. And keep an eye on message boards like this one and others so you know which casinos to avoid.
Hope these suggestions help you with your new hobby, and GOOD LUCK!