Win95 was my favorite OS when all I owned was a Pentium 233MMX with 32mb ram. Win98 was the slowest thing in the world, and still is, now that my dad is using the old machine with SE. With win95, don't update to the new Win98/IE4 GUI. That will slow the system to a crawl (98 speed). Get Dial Up networking 1.4 if you can (most internet connection cd's from MSN, AOL, etc have that) and of course get IE 5/5.5. By the way, how much ram does that pentium have? Don't use some of the newer os's unless you've got at least 64. Seriously. 32mb ram is even slow on 95, and if you have 16, it's time to toss the box or get ram.
Now if you want the GUI to look better without slowing down the system with the 98 shell upgrade, get the font smoother from here:
http://www.microsoft.com/typography/grayscal/smoother.htm
It's called the font smoother, but it gives you all of the "effects" tab under win98. So you can make your icons full color, antialias ( font smoothing; not recommended 'cuz it's slow) make icons bigger, change my computer icon, etc.) Basically this is the incomplete version of Plus! 95. Very useful.
Other updates... well, I seriously recommend using Windows 95B or C (OSR 2 and 2.5) With those you can use FAT 32, and even USB (the usb support is really primative and works with about 2% of the devices out there). Check the verson right now: right click my computer, and check the version. IT should say 4.00.950. After that there may be an A, B, or C. If you have B or C you're fine. If there is nothing afterwards or just an A, try to obtain a B or C version (OSR 2 and 2.5)