The current edition of Silman's book - a great one, I might add - actually suggests that it serves players with ratings of 1400+ best. So, I believe you may have assessed this correctly: it might be your NEXT book, after you've strengthened your game some.
You might try Amazon for a good list. Here's one I found there:
http://www.amazon.com/Best-Chess-Books-for-Beginners/lm/R3T0KSLGYJ5LL2
Best ways to improve ... good question, of course. Playing a lot is great. Play slower games if you can manage that ... slower games allow you to spend some time thinking and not simply reacting. But the best way to improve in a general sense is to go over your losses and try to identify where you went wrong, what kind of error you made, and develop a plan to try to correct that error.
This stategy is outlined very well by GM Kaidanov in his video series here, beginning with this title:
http://www.chess.com/video/player/how-to-improve-your-chess
Best wishes.
Can anyone recommend some good entry level instruction books? I have one authored by Jeffrey Silman titled "Reassess Your Chess". It's a good book, but I question if I'm ready to Reassess just yet. I am gratefull for any suggestion's. Also, please share your thought, I have been told that the best way to improve is to play alot of games? Thank You.