The Messier Objects by Stephen James O'Meara is excellent. I have the Marathon book as well, I think the O'Meara book is better. He also gives you the charts with star hopping seggestions, drawings, and a B&W picture of each item. They are not the best pictures I've seen of these items which is good. There're not exactly what the item will look like in the scope but closer than the beautiful color pictures you see that look nothing like the item in the eyepiece. Everyone acts the 2x Barlow lens is the most important item to buy at first. I have one, never use it. There's nothing wrong with a Barlow, I prefer the eyepieces buy themselves. I don't know anyone who uses a 25MM eyepiece and a 2X Barlow to get the equivlent of a 12.5MM. Most people get an eyepiece in that range. The Barlow is used mostly for real high magnification on the Planets. But a 4MM or 5MM will do the same thing without adding another piece of glass to the system. This is all just my opinion, I've read about some people using it all the time, but from my experience, they are the exception. Your best bet is to invest in some high quality eyepieces. Get one at a time. You'll see a big difference right away. See if you can get to StarParty and try some out. The Televiews are great. Naglers are great by real expensive. Meades are great also. I'd star with something in the 12mm to 17MM range. Maybe get a bigger one and a smaller one later depending on what you can afford. Most of the $200 to $350 eyepiece are well worth the money. The $75 to $100 range will be better than what came with the scope, but believe me, you'll happier with 1 expensive eyepiece than 3 or 4 cheaper ones. You don't need as wide a range of magnifications as you would think. Things don't look that much different at 150x than they do at 125x. Around a 32MM, 17MM, 12MM and smaller one maybe 8MM or smaller later would be a nice range. Plan ahead, be patiant, get one at time. You'll probably never use the ones that came with the scope anymore. Good Luck. Keep us posted.
That's it;
BOB SAL