When stuck with new Betta and nowhere to put them but the show tank, here's what you do:
Fill the tank with conditioned
tapwater (see conditoner below) heated to around 80*F. Float the fish, in their cups, in the tankwater for a half hour or so until the temperatures match. During this time, ladle a small quantity of tankwater into the cups and dump a similar quantity of the cupwater. Repeat until the cupwater has been replaced by tankwater. Sink the cups and let them swim out into the tank.
For cycling, this is the easy way.
No rush. More important are the fundamentals (you sound like you already know some of this).
---Water conditioner. Seachem Prime is excellent. Don't change water without it.
---Heater 50W for that 10g tank
---Thermometer. Glass, not stick-on
---Water test kit: [ame="http://www.amazon.com/API-Freshwater-Master-Test-Kit/dp/B000255NCI/ref=sr_1_1?ie=UTF8&qid=1349945368&sr=8-1&keywords=API+test"]Amazon.com: API Freshwater Master Test Kit: Pet Supplies[/ame]
---Siphon (aka gravel vac) for cleaning the substrate and water changes. Small size will do.
---Get a few silk plants or, better yet, some live Anubias, Wisteria, Java fern, Java moss or other beginner plants. See plant stickie in the Tanks and Habitats section.
---a small pot or cup for them to hide in
Other advice available in several stickies at the top of the Betta Care section and the Tanks and Habitats section.
Good luck.And welcome to the forum.