By plane:

from Milano Malpensa Airport

CAR 0h58: take the SS336 and the E62.
Another option is to take the E62 and follow Via IV Novembre, which is longer.

BUS 1h54: take a bus from Malpensa Airport (Terminal 2) to Omegna (Piazza Beltrami) via Fondotoce (Piazza Adua).
TRAIN 3h35: take a train from Malpensa Airport (Terminal 1) to Busto Arsizio Nord, then Novara Nord and finally Omegna (Piazza Beltrami).

from Torino Caselle Airport

CAR 1h30: take the E64 and the A26.
TRAIN 4h08: take a train from Torino Aeroporto Di Caselle to Torino Porta Susa, then go to Novara and finally to Omegna.

from Milano:

CAR 1H16: take the E62 and follow Via IV Novembre.
TRAIN 2h41: take a train from Milano Centrale to Omegna via Novara.

from Torino:

CAR 1H36: take the E64 and the A26.
TRAIN 3h00: take a train from Torino Porta Susa to Omegna via Novara.

from Novara: 

CAR 0H59: take Corso Risorgimento and follow Via Novara.
TRAIN 1h03: take a train from Novara to Omegna via Novara Nord.

from Varese:

CAR 0H55: take the E62 and follow Via IV Novembre.
TRAIN 3h46: Take a train from Varese to Omegna via Busto Arsizio Nord, Novara Nord and Novara.

Where can I eat:
La Buvette Lago D’Orta
Ristorante Punti di Vista
Osteria Trattoria Speranza
Ristorante Ponte Bria
Matisse Omegna Food & Drink

Where can I sleep:
B&B
Vaemenia
Porta Romana
Villa Carola
Antica Corte
Casa Rosa
Chocolat Au Lac

Apartments
Al Poggio
Poggio San Fermo