Don't put off networking together your collection of desktop computers just because it costs too much to hire a trained installer. You can do it yourself if you have a little skill, a modicum of motivation and a passel of patience.

Many problems used to plague LAN installations, both in setup and in running the network. The Novell company engineered a sophisticated product line that solves most of those problems. That, plus the company's aggressive marketing, account for the fact that a large share of LANs installed this year will use Novell software and Novell or Novell-compatible hardware.That's why our most recent test installation used Novell to link our four IBM PC compatibles, Macintosh IIcx and three printers. Some of the hardware we linked is in a separate building. The skills we needed are the skills an average computer-owning reader possesses. It took less than a week of spare-time effort to make it all work together.

In Novell networks, the hardware consists of circuit cards that fit inside the networking PCs. Once installed, the accompanying software directs their communication. It enables the PCs to all share the same files and printers. It makes sure that no two people can make changes in the same file at the same time (an event that otherwise results in file garbling).

If you're game to try your own installation, we recommend Novell ELS Level II Version 2.15. (ELS stands for Entry Level System.) No-vell's software consists of a large collection of programs - 40 disks' worth. Some of the functions they control are essential, such as supervising MS DOS and MacOS chores. Others are useful, such as handling E-mail, keeping an appointment log and creating easy-to-follow menus for network users. Still others are, frankly, frosting on the network's cake.

Expect your ELS LAN to cost about $1,500 for software and $500 per computer for hardware. (Installation by a professional consultant adds about $2,000 to $4,000 to the bill.)

Before you buy any network package, carefully read Novell's product literature. Note the guidelines for selecting the best circuit boards for you. (The boards are also referred to as network interface cards and adapters.) Novell sells four boards for use in IBM compatible PCs. One is for older PCs, another for AT types and a third for PS/2s.

They all interconnect easily. Mac-intoshes connect into the circuit in two ways: You can add a circuit board to the Mac or put an extra circuit board in the network's file server.

We recommend Novell's Ethernet LAN adapter boards. If you go with boards that use a cheaper grade of wire, you could end up getting lost during the installation. Any money you save will vanish swiftly if you need an outside pro to bail you out.

One key part of the planning phase is selecting the file server. That's the computer that holds the hard disk that stores the network files. It can also store most of the files each user works with. A good rule of thumb is the bigger the disk, the better.

This computer can be used as either a dedicated or non-dedicated file server. If it's dedicated, it works only for the network. You'll hardly touch its keyboard. But a non-dedicated server needs a lot of RAM memory, at least 3M. It costs more to beef up memory so it's adequate to perform as a non-dedicated server than to use the computer as a dedicated server - unless you buy and add the chips yourself.

While you're figuring costs, don't forget to add the cost of wiring together network computers. (You can run network cable for hundreds of feet.) Novell circuit boards use coaxial cable. Each adapter comes with a 25-foot network-ready cable and local electronic suppliers can sell any extra you may need.

When you've done all the planning and bought the Novell boards and software, be sure not to skip phase 2: Study the manuals. In particular, read carefully through the installation manual and fill in the work-sheets using pencil in case you change your mind.

That done, you can move on to phase 3, hardware installation. If you've comfortably completed some installations we recommended in previous columns, such as adding a new disk, installing these circuits will be a piece of cake.

Novell even includes a program you can run to test that each circuit card is properly installed.

Phase 4 requires installing the bulk of the software. We urge first-timers to use the default settings. It makes the whole process quick, easy and foolproof. Later on, you can customize to your taste. Nowhere in Novell's planning manual does it say how much space the software needs on a hard disk. Ours sprawled out onto four megabytes.

Phase 5, readying the LAN for every user, may be the toughest.

Novell doesn't put its guidance all in one place. Most of it is scattered in the task lists that dot the technical manual, especially in lists headed users, mappings, menus, print jobs and login scripts. If all else fails, you can't call Novell's technical support for free help with ELS. You have to count on assistance from the dealer who sold you the parts.

Think you can do the installation we mapped out? Then you probably can.