Preparations for The Show are not delayed by the hot and humid days of summer: The teams are practicing blocks, passes and tackles. Band members are rehearsing their music, dance steps and regimentation. Cheerleaders are jumping, flipping and cartwheeling.

On the sidelines, finance officers have visions of dollar bills dancing in their heads and fans already are counting on having a team that is the best of the best.

The football season is at hand.

It is not the season of highly paid professionals. It is the opening (under the lights on Friday, Sept. 5) of the Northern Virginia high school season, a season that has become a mirror image of the game played on college and professional fields.

Administrators, coaches and athletic directors agree: A successful football program can provide a school with spirit -- and money.

In recent years, high school football has held its ground against attackers who cry "Unsafe!" and against challenges for the spotlight from other sports. Throughout Northern Virgina, preparations for the 1980 season are drawing record numbers of students who want to be part of the spectacle that is high school football.

At the 27 Northern Virginia high schools, about 2,500 students will suit up this season. Another 5,000 will be involved in support groups like marching bands, cheerleading squads and pep clubs.

Each school can expect to gross $9,000 to $25,000 a season from gate receipts alone. Tickets cost $3 at the gate, $2 in advance for adults and $1.50 in advance for students. Concession sales, traditionally run by parent booster clubs, add even more to the game's profits.

In fact, schools depend upon football revenues to provide 80 to 90 percent of their total athletic budgets. Despite complaints from other participants in other sports about the heavy emphasis schools place on football, the game helps support the nearly 30 other sports in every high school in Northern Virginia. "What the football program does financially is crucial to the athletic budget," says Al Frazee, athletic director at Oakton High School. "If it doesn't do well, it's rough to support the other sports."

Area schools spare little in the way of money, preparation or support to develop a successful football program. Helmets, for instance, which must conform to nationally imposed safety standards, cost $65 apiece. Shoulder pads cost about $50, game jerseys $20 and pants with hip pad inserts, $20.

Football coaches use headsets, walkie-talkies, movie cameras, projections and even computers to help them run their programs. (Some equipment -- like the computers, projectors and camera -- also are used by other school programs.) All area football teams film their weekly games at a cost of about $2,000 per team for the season.

Coaches use the films to grade their players' game-to-game performance. Coaches also exchange films with one another to help prepare for upcoming opponents.

To make sure their athletes are in top form, coaches encourage year-round training. Throughout the school year, and into the summer, many local football hopefuls pump iron on school-owned weight-lifting machines; cost -- $2,000 plus).

"We put the players on an extensive weight training, running and agility program two nights a week in the summer," says Chuck Sell, a head coach for 31 years, the past eight at James Madison High in Vienna. "The kids want it. We don't have to force them.

"The pros do it. The collegs do it. High school teams throughout the country have these programs. Competition makes it necessary."

Some teams, like the one at Madison, spend a week ever summer at football camp on a secluded college campus. The camp costs $75 for each player and is paid for by each team member, not the school. Every day starts at 7 a.m., with three practices a day.

The rising cost of keeping up with the competition has made coaches, who mustalso be faculty members, well-schooled in the art of fund raising. In fact, most coaches give it a high priority on their schedules, which during the season include 40 hours a week of football-related matters in addition to any teaching duties.

"We put $9,000 worth of equipment into our school's weight room this summer and it didn't cost the county (Fairfax) a damned thing," says Ed Henry, head coach at Robinson High in Fairfax. "We paid for it by saving towel rental money (an optional service paid for by physical education students) for three years. We go a smorgas board of weights that can be used by the whole school -- three new pieces for our (weight machine), neck strengthening machines, pullover machines, knee strengtheners and four sets of free (unattached) weights."

A school often takes extra steps to support its football team.

In the past, the booster clubs at some schools have paid to take busloads of students to away games, at a cost of $1,600 to $1,800 a season.

As part of a week end retreat for student leaders, John Alwood, principal of Lake Braddock High in Fairfax, intends to get the students' "imput on how to generate more spirit for the football program. Attendance at home has been good, but we haven't taken good crowds to away games."

Last year, Oakton High School in Fairfax sponsored a Kick-Off Night featuring local sports caster Ken Beatrice. The team and coach were introduced to an audience of parents and students from the Oakton community.

"We try to make sure the kids see the value in what they do by showing them the school is behind them," says Oakton's Frazee. "You do everything to make programs successful. You provide as much as you can to keep the coach and players happy."

Frazee adds, "A winning football program is important to the total school program. If the team makes the student body proud, things go along much better for the whole student body. It's a matter of morale."

Madison's Henry calls football "the harbinger of a school's extra curicular activity for the year. It's easier on every one if we're successful."

And success, even at the high school level, seems to follow the old Vince Lombardi rule for winning. Winners, like Annandale, Madison and Robinson, consistently produce $18,000 in revenues each season. Losers, on the other hand, have a hard time keeping up school spirit and bringing in the money.

By the end of the season last year, Cahantilly's gate at home was only half of what it was at the start of the season," says Ken Poates, who is begining his year as head coach at the school in Fairfax.

Poates' first order of business has been to turn around the team.

Within a week of when I was named (in May), I had met all the players," he says.

By the time practice opened Aug. 12, he had met the team's booster organizations, selected his assistants, established a training program three nights a week and "met with youth football league coaches in the area to help build the high school program in the future."

Poates says football, even high school football, appeals to spectators because it is a "glamorous sport. Henry says games are where "people go to see and be seen." Although adds, "Let's face it, in our society, football has a lot focused on it."

Nearly everyone, it seems, wants to be a part of it.

In many schools, marching bands work out as long as the football teams. Band directors talk of "psyching up" for half-time shows and band members even have to do calisthenics at practices.

"The kids loved performing for football games," says Jim Stegner, who was band director for nine years at Falls Church High, traditionally one of the most highly regarded high school marching bands in the country. "At home games, we loved the recognition. At away games, we loved to just blow the crowd away."

Falls Church has 180 members in its band, including a contingent of 38 flag bearers.

At Mount Vernon High, the 135-member band includes a drill team and color guard complete with flag bearers and a rifle company. Director John Casagrande notes that Mount Vernon's band, and others in the area, perform at numerous functions not just a football games.

But, he admits, "more people will see us at the half-time of one football game than at all of our concerts put together."

Adding to the spectacle, of course, are the cheer leaders. They perform for many sports, but "football is still the main one at most schools," says Kathy Flinn, the faculty member who supervises the cheer leading squad at South Lakes High in Reston.

Cheerleaders will attend summer camps ($88 person -- half paid by the cheer leaders and the other half through fund raisers, Flinn says), learn the latest routines (gymnastics and dances are popular) and practice two hours a day from early August to the end of the school year.

Why do they do it?

To be part of The Show.