I also really like Picasa, and still find myself only opening Lightroom once I pick out the favorites for retouching and fixing. I do the bulk of inspecting a shoot and just general organizing my accumulated files, from right in Picasa. The price is right too - and it's built in editor tools honestly are fine for the little fixes that one might need to do . . . there are lots of photos I keep just for myself, that I do not have to share with clients, publish online a portfolio, or print - I'm happy with the minimal tweaks available in Picasa, for things that are only important to me. I believe these are called "snapshots" lol!
I'll speak now as someone coming from the tech fields - you also need to have some organization among the raw folders where you're sticking your pictures, something that makes sense to you. (...and you back it all up frequently, RIGHT :D?!?) I'll share mine, and I'm sure others have shared their own methodology in older threads. I loathe data recovery jobs where people have their files all over the damn place, no discernible methodology or real assurance I got "everything" before Wheezy the Sad Hard Drive gave up the ghost.
I find that at this point, I am shooting a dozen or so - give or take - times per month, usually hundreds per session. Some are just for my own interest, some are for clients. At this point, I am okay blending those but I can see the day coming when I might prefer one more layer of sorting . . . but for now, that's my workflow and storage, personal and business alongside each other. Inside the My Pictures folder, I have subdirectories that are years. Obviously those line up nicely, one after the other, so just the numerical value works. Inside those directories, I have the months formatted as "01-2011" for January 2011, then "02-2011" for Feb 2011, and so on. I do it this way because that forces them to line up nicely in Windows Explorer, by date. Yes, you can tell it to sort literally by date too, but sometimes my file dates are not the same as the shoot dates and it gets mucked up. This way the folder titles force it to be chronological, which is helpful when I am looking for photos from a certain shoot.
Inside the month folders, I use proper names to describe the shoot. I do not so much care if these line up chronologically inside the months, because (in my memory) it gets a little muddled anyway - I just remember that I shot this client and all those sunsets, both in Decemeber. Each has a folder with a name that makes sense to me. And as I said, it's only a dozen or so each month at this point, easy to glance at that list and find what I want fast.
Oh, and when I edit something in LR, polish it up for presentation of some sort, I always export it with the file name "LR_pentaxfilename.jpg" to easily differentiate it - and I drag it (in Picasa) to lie next to its original.
I am trying to be better about tossing the Meh photos sooner and more ruthlessly, but it's hard when hard drives are so cheap, lol! Poor motivation :-P. But I do like to be able to look through a folder in Picasa and just enjoy the best stuff. I often take a large number of photos of the same thing, to get The Picture (I'm sure we all must) and I try to sift through those and toss the ones that don't make the cut right away, it just gets so, so clogged with 100 photos of a rose, you know? It also makes me a better editor, to not spend ages attached to mediocre photos, I think. I find it very hard to go back to those old, bloated photos and toss stuff a long time after the shoot, I wonder what is up with that???
Give Picasa a whirl, it really is a great "first layer" tool - LOADS better than just Windows Explorer, not huge/expensive/overbuilt for basic sorting (and tweaking snapshots nobody else cares about) like Lightroom.
