Don, I would still consider myself a newb, especially against these guys but I have learned and experienced a lot in a short time (but never done learning). What you really want to do depends a lot on budget, reliabilty desired and how much you want to 'play' with it. I too started from ground zero that spawned from a $9 HAL Deluxe starter kit from Lowes.
If budget is the biggest obstacle than you do probably need to stick with x10. As with most things though, you get what you pay for. I've read a lot of posts and while there are many people using it successfully, the majority seems to be a bit unreliable without a bunch of tweaking (phase couplers, amplifiers, filters, checking signal strength, etc.).
For that reason and since I had the luxury of starting from the beginning, I chose to go the UPB route. I do have a few of the x10 switchlincs to control flourescent loads, and even with only 3 x10 devices I am having issues with them not working - probably due to phasing or low signal. And, depending on the size of the system, the price barrier really narrows down. By the time you throw all the couplers, repeaters, filters, etc in the mix you could pay for a few more quality UPB devices. These things are usually avoided with newer technologies. As BrianD pointed out, and I agree for many reasons, I am not a fan of wireless.
On the software side I have only used HAL and Homeseer trials and I can not give you much feedback there. But on that note, have you considered a Hardware solution? If you really want reliabilty and not messing with a pc, this is really the route to go. Especially if you also need a security system, or have an aging one in need of replacement.
That's the route I went - I chose an Elk M1G after 'studying' here for a while. There are other good controllers out there, like the Omni, Stargate, HVPro? and I'm sure others, and there are users and experts of those systems here as well. The M1G is the newest of the lot and seems to be a current fan favorite. Another factor for me was their (Elk Products), support. Heck, even their chief engineer (Spanky/David) hangs out here and expertly answers questions. You just can't beat that. In that respect, back to software, even though Homeseer is still a crowd favorite, I would take a really good look at CQC (Charmed Quark) since the chief developer/CTO, Dean Roddey (above post), is very active and supportive here.
So far, I'm trying to keep on the hardware only side, although I am struggling a bit in creating some rules that I know I can code quickly in some of the SW packages. I probably can still do it, just need to get a bit more creative.
Anyway, hope this helps and if I've mispoken I'm sure one of the vets here will correct me. Good luck with whatever you choose.