I'm a newbie, too. I say the monitor is big enough, but bigger is always better. Same with the PC. I have a Pent 4 1.6, gig of ram and can play Mortal Kombat 3, Tekken 2, NBA jam and others well. I can't play Tekken 3 and many other 3-D games. If all you have is a Pentium 3, it will play most older games, say 1990 or older. You can give newer games a shot and see how they play, tho. Get a good Front End, command line emus, follow the Wiki or use total sheller to hide windows and minimize PC power sappers. There are great GUIs out there (MameUI is a Mame GUI) but you'll want to use command-line emus for the cabinet for sure. If you're intimidated, go with Mala or another easy-to-use Front End. Mamewah is harder to set up (I'm not tech savvy and I did it fine) but many here say it's very stable. I use Mala now and really like it. Command line emus will perform better and will hide windows perfectly, which you'll want. Also, you can do about everything without a mouse or keyboard when it's set up.