Welcome to the forums Tereva!
I'll echo exactly what AntFreq is saying on here (he's the best expert we've got!) I'd recommend saving a few more bucks and going with a Digital scanner. It'll be worth the money and won't become obsolete in 10 years. Not saying that analog scanners will be obsolete, but you'll be able to hear almost everything in 10 years when most, everyone is digital.
Looking at the RadioReference Database, it looks like Yuba City Police is currently mixed-mode digital, so if you're going to want to monitor them, you'll need that $400 scanner.
In the meantime, while you save, you can get a cheaper Analog Conventional scanner (doesn't do digital or trunking) for around $20-40 bucks on ebay. Of course with ebay you are taking a small risk, but for $20 bucks, you'll probably be ok. Most of the stuff up there is analog right now, but CHP is using digital for their vehicle extenders, Yuba City PD is beginning to go digital, Beale is all digital, and you'll start seeing digital up there pretty quick.
That said, if you'd like to spend the $200 right now, the BCT15x is a GREAT scanner. The best part is, you can get a paid membership here for a few bucks, download a program called FreeScan and you can program it with your computer, and automatically download ALL the frequencies from RadioReference's HUGE database, and with a few clicks, program the scanner to your liking.
The one problem you might run into it does have quite a few bells and whistles, and it takes a little getting used to. It's not like your current scanner, it's a little more complex. You won't need a PhD to figure it out, but it may take an hour or two for you to really get going with it. In a couple days, you'll be a pro. I know it sounds like a big time investment, but it's not. If you take your time, be patient, and ask lots of questions (you can always feel free to PM me and I'll do my best to help) you'll be operating that 15X like a pro, and you'll be even more addicted to Monitoring.
Hollar if you need any help, we're always happy to assist. You're lucky enough to be in a GREAT location for monitoring.
EDIT: Oops! Almost forgot. Up at the top of all the RadioReference pages, there's a menu that says "Wiki" it's got a GREAT glossary for learning about all the different acronyms, digital/analog/trunking - all that good stuff is explained in the Wiki. The search feature for the website up at the top can navigate you to those sections as well. I learned A LOT from that Wiki since joining RR back in the summer of '05. Now I'm a licensed Amateur Radio operator and I'm about to go get my General Radio Operators License (basically a license radio technicians get that many radio shops require) and it alllllll started by buying a cheap scanner on ebay, and joining this site.