Bus:
There's a regular bus # K-678 daily from Ozerki metro station in St. Petersburg (North). The bus departs Ozerki at 9am, 11am, 2.30pm, 4.30pm, 7.20pm, 9pm and takes about 1 hour 50 minutes to Korobitsyno (Krasnoye Ozero). The bus from Korobitsyno to Krasnoye Ozero departs at 6.30am, 7.20am, 11.40am, 1.40pm, 5.10pm, 7pm, 9.40pm and also takes about 1 h 50 minutes.
Train:
Take a train to Sosnovo from Vyborsky station in St. Petersburg, and then from Sosnovo buses 645 or 646 or a taxi towards Korobitsyno. Stop at Krasnoe Ozero resort. Total travel time about 2 hours. The local bus schedules are a mystery, so if unsure in your Russian skills, it's better to take a bus from Ozerki metro station.
Driving:
Take Vyborgskoe Shosse towards Finland. Turn right to Pervomaiskoye and drive up to Podgorie. Then turn right towards Michurinskoe. The resort is near Korobitsyno village. The driving time from St. Petersburg is 1 to 1.5 hours.
For driving directions and a road map, see the resort website at http://www.krasnoeozero.ru/_w/rl_map.asp
Flying:
The planes to St. Petersburg arrive to Pulkovo airport, which is quite far from the resort. You will need to go across the city and drive towards Vyborg.