Don't be afraid to admit that you're new to this stuff... everybody had to start with the basics some time.
First of all you should get a decent PC - although you can use almost any PC to make the conversions it'll just work faster and better and you'll have less overall problems. So get a Pentium 3, Athlon or Duron processor at 800MHz or above, a 40+GB major brand 7200 rpm hard disk - Maxtor and WD are pretty good - a quality ASUS mainboard (or whatever brand you prefer, MSI & Abit are also very decent) - accept no less - 256MB or more DDR RAM, a decent modern graphic card - NVIDIA RIVA TNT and above (TNT2, Geforce 256, Geforce 2, Geforce 3, Geforce4) have worked flawless for me, they have about the best driver support and are also very decent 3d accelerators and a decent DVD-ROM - check this page for drives that can be made regionfree. As soundcard I suggest a Creative Labs card, either one from the Live series or an Audigy. The exact type does not matter, they're basically all the same and most importantly they support 48KHz sampling.
Also.. I hate brand computers. I always assemble my computers on my own because they work much better and if something is broken it's easy to find a replacement. Also.. there's no chance of any component being cheap shit and since I decide what components to put in I can make sure that I have good support for everything. If you don't know how to assemble a pc and don't have a friend who would do it then have it assembled in the store.
The next important choice is the operating system: Don't accept anything less than Windows2000. Windows 9x and Windows ME are CRAP!!! Even some Microsoft executives say that Windows ME is nothing more than a toy operating system - check The Register for the story. Besides the operating system you probably want to have a decent DVD player. Both PowerDVD and WinDVD have worked flawlessly for me and therefore I suggest you get one of those. An alternative is the RealMagic Hollywood Plus hardware card.
Now this is crucial: Install Windows2000/WinXP from scratch - no updates, no overwriting of the older stuff... make sure your hard disk is empty then install it. Then install the most recent drivers for your hardware - Liveware, the latest Graphic Card drivers, Drivers for your modem, network card, Hollywood+ and whatever else components you may have. It's also suggested that you only have one DVD software player on your computer since they all have their own playback filters and they might screw with each other. Don't install too much software, only the stuff you really need. The more apps you have to more unstable your system gets - although Windows2000/WinXP almost never crashes it will get slower and the more apps you have to more dlls, vxds and other useless components you have lying around that might interfere with your ripping software.
You may also try after setting up your soundcard and graphics card to just install the ripping software - the DivX codec is about the only thing you really have to set up unless you use commercial software like the Panasonic Plugin, CCE, LSX, etc - and then try to make the first rip.
You might also consider making an image of your harddisk so you won't have to reinstall all the time but you can simply put the image back on your harddisk and you'll have a fresh system. As imaging software I suggest Norton Ghost. This software can write an image to a bootable CD-R so if your system becomes unstable or slow again all you have to do is boot from that CD and write the image back to your harddisk which saves a lot of time compared to a reinstall. You have a fully working system again within 10 minutes so I strongly suggest you go for this solution. It certainly makes the dreaded Windows reinstall a lot less painful.
There are certain command line based utils that are being used and described on this site. These utils are: VobDec, mpeg2avi, ac3dec, vstrip, aviac3split, Synch.exe, vidtoasf, decodevob, azid and bbTools. To run these utils you can't just double click on them in Explorer, you will either have to start a command prompt (press Start, Run, command (for Windows98) or cmd (for Windows2000/WinXP)) and run the program there (usually when you type the program name without any options it'll give you a list of the command line options, or you can enter : "programname -?" or "programname /?" or "programname -help" to make it show all the options. Needless to say that you have to be in the same directory as the program resides. To learn more about command line stuff I suggest you get a good book or just type help and read what it says. The other solution is to use a GUI: Graphical User Interface. For instance VobDec GUI and cladDVD are GUIs for VobDec. There are no GUIs for aviac3split, Synch.exe, vidtoasf, decodevob and bbTools!
If you're going to rip to DivX I strongly suggest you start out with GKnot. While the learning curve is a bit steeper than with FlaskMpeg, the results will be much more satisfying. GKnot basically has no synch issues when you follow the guides, and no problems with aborted conversions or crashes. Plus, 2 pass DivX3 and DivX4 encoding is made really easy using GKnot and you get better video and audio quality than using FlaskMpeg.
If you want to make an SVCD rip DVD2SVCD is the way to go. For VCD I suggest DVDx using the built-in encoder.
Despite the guides you may run into problems. The IRC channel (#doom9, #pcdvd, #divx-rippers on EfNet, or the forum are your stops to get help. But please make sure that you truly understand the guides that matter before asking. It has happened to me zillions of times that somebody asked me something that was already answered in my guides or that he had a problem because he simply didn't carefully set the program up. Please spare me the frustration and make sure you triple-checked everything before asking any questions.
Also: From my experience I'd say that at least every 3rd error that happens when somebody is ripping is due to a screwed up configuration. Even Windows2000 requires periodic reinstalls without prior deleting of every file associated with it (so in other words the c:\windows, or c:\winnt directory has to be erased completely). I've been in the PC business for 8 years now and in the old days I had to reinstall Windows 3.1 every 3 weeks or so and now with Windows2000/WinXP I'm up to about 2-3 months but I still do it. Some day something is bound to screw up your system. The more frequently you install software the more likely it is to happen. The more hardware you have into your PC the more frequently it's bound to happen.
Concerning decryption: There's a detailed guide which covers all imaginable cases which is linked from any ripping guide on this page.
And last but not least: I've ripped way more than 100 movies, all successfully synch and in perfect quality at the end. I've even managed to rip films that had changed titles keys in the middle of a vob files, multiangle movies when there was still no multiangle-capable programs out there, etc. With a few exceptions I've tested all the methods described in the guides you can find on this page.. so trust me, they work just fine. When something doesn't work according to the plan then it's highly likely that you didn't follow every step in the setup.
That's about what I have to say to you. Take your time to follow all the steps in the guides. It may take you longer before you can start ripping then with other guides but it'll avoid you much frustration.