I found a Windows 95 104-key keyboard at a computer superstore for $15 on the bargain rack. It was from a HP system that someone had returned, and it was a much better deal than the off-brand selling for $25. I go through keyboards about once every two years. Keys break, I'm not particular about what brand they are, and I generally don't care when and where I buy one. While buying components for a PC I was building once, I got bored and asked the salesman how much a keyboard was. I bought it sight-unseen for $30 and I was happy for two years.
The only useful thing I can add about keyboards is that there are two types of connectors in use: one is small (PS/2 style) and the other is a little bigger (AT style), but an adapter can be bought for either one if you have the wrong kind.
For the nostalgic, it is of note to mention that the IBM keyboard has a patented design, a heavy tactile feel, and generates a loud, monotonous click when used. For people who got used to the IBM clicky keyboard and if you had a cheap-o keyboard, there were many utilities available in the mid-80's that would cause your PC speaker to chirp every time you hit a key.
If you've ever watched an audio CD player that had a clear case, you may have noticed the head starts reading at the center while the CD spins fast, and continues to the outer edge where the CD spins much slower. Audio CD players and single-speed CD-ROM's read data at a constant 150 KB/sec. Each multiplier of this speed makes the data transfer rate faster, so a 12X drive reads 1800 KB/sec, still much slower than any hard disk. As with hard disks, SCSI and ATAPI IDE drives are available. For those laptop guys out there, there are parallel port drives, too.
A CD-ROM drive reads disks differently from a hard disk, in that it spins at a constant linear velocity (CLV), instead of a constant angular velocity (CAV). Let me revise that statement. I have just seen the specs on the latest "16X" drives. These newest drives borrow the CAV technology of hard disks so the drive can spin faster. This means that there is not a constant data transfer rate across the CD (more data per rotation can be stored in the outer regions). It's difficult to explain, but essentially by utilizing CAV techniques, the data transfer rate can be significantly increased for the majority of your data. In simple terms, the transfer rate may start at 1800 KB/sec (12X) and increase to 2400 KB/sec (16X) at the end of the disc.
If you want two of your home PC's connected at a reasonable speed, Ethernet is perfect. You'll need Windows 95, two Ethernet cards, and a Category 5 cable that has had its send and receive wires crossed (you will usually have to make your own or buy it custom-made). Once you change a few network settings, you'll have a 10 Mbps (1.25 MBps) connection between the two computers, which is over six times faster than a T-1, ninety times faster than a serial port, and one-tenth the speed of SCSI-2.
There are at least two options now: optical disks and magnetic tapes.
The PD is a hybrid CD-ROM 4X reader and a PD disk read/write drive made by about a half dozen companies in SCSI and IDE formats. It is quite a good compromise if you don't already have a CD-ROM or a tape drive. Each PD disk holds about 650 MB and can be written like a (slow) hard disk. The best thing: it isn't a WORM; you can rewrite it hundreds of times. Other good options are the new QIC drives called Travan. Try to get one that uses the TR-4 data cartridge, which holds 4 GB native. These things are as good as the DAT drives that cost much, much more.