I've been there twice in the last two years. The O'Connor book is good, but dated. Check out Razzetti, Trekking and Climbing in Nepal (get the 2008 version). If you want to be on your own, avoid the popular NMA trekking peaks (Island, Mera), although both make good trips with Island probably an easier self-contained trip. Kyajo Ri is a great NMA trekking peak if you want be out there some and, while it is true that you are supposed to have a guide, it is possible to go on your own with a little convincing. Check on Joe Puryear's post here:
http://climbnepal.blogspot.com/2009/04/success-on-kyajo-ri.html
The nice thing about Kyajo Ri is that you can do it from Namche packing in your own kit. The trek around the Khumbu and over the passes (Rhenjo La, Cho La, up to Kala Pattar and back to Namche) is a good acclimatization plan. For the basics, both the Lonely Planet "Trekking in Nepal" and Jamie McGuinness' book "Trekking in the Everest Region" are good and both offer a different perspective. I'd recommend Climb High Himalaya (www.climbhighhimalaya.com). An agent like Climb High or others mentioned here, can get all your permits and bs squared away and, hopefully, help you avoid the NMA "guide". Lobuche East could be an easier alternative to Kyajo Ri, but it will have plenty of guided groups, which you might be able avoid if you do your pre-trek and then try to hit it at the tail end of the season at the end of October/early November. This is another good site (http://www.nepalmountainnews.com/cms/), but the information can be a bit dated. Finally, I read there may be some new NMA peaks opening up and some general rule changes possibly being implemented next year so keep you eyes open for that and be sure to ask your agent about any new rules. Oh, and the National Geographic maps, both the Khumbu (larger area) and Everest Base Camp (not sure if Kyajo Ri is on this), are good along with the Schneider Khumbu map for a little better topo feel (Kyajo Ri definitely on this).