It is getting-down-to-business time in college basketball, that anxious period when the early season exploring gives way to the new year and the often-harsh realities of conference play.

The transition probably could not have come at a better time for Maryland, which enters tonight's Atlantic Coast Conference opener at Wake Forest riding the crest of emotional victories over Rutgers and South Carolina in the ECAC Holiday Festival in New York.

Georgetown, meanwhile, probably is just as fortunate that it has a final tuneup -- tonight against Jackson State at Capital Centre -- before Saturday's onset of the Big East season. The status of forward Alonzo Mourning's ailing left arch remains uncertain.

Also tonight, Navy hosts Lafayette in what almost is a league game: Next year the Midshipmen will join the Patriot League, in which the Leopards play. Navy, playing its first home game since Nov. 26, begins its final season in the Colonial Athletic Association Saturday against East Carolina.

Other area colleges take to the road tonight. George Mason will play Virginia Commonwealth at Richmond Coliseum, 18th-ranked Virginia will try to extend its five-game winning streak at Marquette and Howard faces the daunting task of trying to end its five-game losing skid at Georgia Tech.

Residents of the top 10 notwithstanding, perhaps no team in the country is feeling better about itself than Maryland. As the Terrapins followed their 78-69 upset of then-No. 12 South Carolina Saturday by cutting down the nets at one end of Madison Square Garden, the NCAA sanctions that hover over the program were forgotten temporarily.

But as Coach Gary Williams stressed yesterday, the only way for Maryland to ease the sting of a year without postseason play is to fare reasonably well against ACC competition. The Terrapins were picked almost unfailingly to finish last in the league, a fact that has raised Williams's competitive fire for nights like this.

"You hang your hat on what you do in your conference," he said. "I think we'll win some games in the league and I don't think we'll finish last, but now we have to go out and do it. . . . The {Rutgers and South Carolina} wins will help us because you need confidence in yourself to compete in the ACC. What we have to watch is that we're not so happy about winning up there that it takes away from our intensity against Wake Forest, because those games really were just something to build on for the conference season."

The Terrapins (6-3) have won four straight, one short of their longest surge under Williams. They had been winless on the road until the trip to New York, and they likely will need the same kind of poise and balance -- all five Maryland starters scored in double figures against South Carolina -- if their winning ways are to continue.

The Demon Deacons (5-2) should provide a stern test. Many ACC coaches feel that Wake Forest's talent level may be behind only Duke's and North Carolina's. Particularly fearsome are the starting forwards, 6-foot-8 sophomore Chris King and 6-7 freshman Rodney Rogers.

The teams split two meetings last season, with Wake Forest ending a 14-game ACC losing streak at the Terrapins' expense in February. The Demon Deacons also faced high expectations a year ago before losing their first 11 ACC games; Wake Forest has not had a winning season since 1985 and no current player has experienced more than three ACC victories in a season.

Georgetown (7-2) probably will not be pushed very hard, for Jackson State's record is 5-8, it has lost six of its past seven games and fell to Arkansas by 38 points Saturday. Yet the 16th-ranked Hoyas, who host Seton Hall Saturday, are biding their time: Mourning continues to be evaluated on a day-to-day basis, and he is listed as questionable for tonight's game and seems unlikely to play. Most distressingly, an aggravation of the injury has occurred each time the 6-10 junior's return seemed imminent.

The latest came near the end of Friday's practice, when Mourning landed after shooting a jump hook. He missed Saturday's 63-51 triumph over Houston in St. Petersburg, Fla., and has played in only one game in the past month.