I think the first think you should do is play in some games online and get familiar as a player. If you are running your own content, horse around with that until you have the feel for playing online and then run a few combats to get going.
Here are my tips. If this all sounds like too much work, it doesn't have to be. Mostly if you can roll dice and get pictures up there you are 90% good and can play.
- How to get tokens, maps, or pictures into the tool and resize them, ahead of time and on the fly.
- Apply a grid if you use one, figure out how to adjust unit size.
- Learn how your tool points at things so you can say "This thing over here?"
- Learn how to get characters and NPCs into the tool.
- If your tool has macros or stored dice rolls, figure out how to roll arbitrary things.
- If it's a desktop tool, figure out how your firewall works with it ASAP.
- Figure out how you are going to communicate: (Discord, Skype, Roll20 chat?)
- Learn how initiative works.
- Get some maps and tokens. I like Fiery Dragon's Counter Collection Digital but there are lots of options. Roll20 has a built in store for those, and you can buy some tokens for FGII from their store. Everything will let you use your GIFs and JPGs. Maptool has another tool called TokenTool that lets you screenshot pictures and put them into rings or squares to make tokens.
- If your tool is fancy, you can draw maps too.
- Learn to center the view for your and players.
- Get comfortable with switching maps. Having multiple maps means each can have its own scale and they'll load faster for players. I think in all of them you can put some players on one map and some on another.
Don't panic. If everything goes to hell you can roll your own dice, use paper sheets, and just throw up a grid to fight on and nothing will be much worse than gaming at a table. And you only have your own cheetohs to clean up.
: Learn everything about how it works, including targeting, planning encounters, using modules, etc. The more you understand how it wants to work the less you'll fight with it. You'll still probably fight with it if you are like me.Maptool:
Just make sure everyone has Java and Maptool installed beforehand and your firewall works. Maptool is great at enormous tiled maps, so if you plan to attack from a mile away in 5' squares, you can. Set up C&C specific properties in your tokens, at least one set for characters and one for monsters. That makes it easier for your or your players to write macros that reference those. If your players are programmers, if you give them a few properties just for throwing random JSON into they can come up with some pretty cool interactive sheets. The weird macro system I wrote for it uses JSON to store weapon inventory and other attributes. If you have time, make a base token for monsters and maybe a fancy one for each class. I can show you some examples. Then you can copy those if you need them. And you don't really need to do any of that to just use it as a dice roller and map.
Learn how to double click on a token in the token list view to center yourself on a monster or player or use the /center command.Roll20:
Discord and Skype work pretty well. You can also set up/rent a mumble or teamspeak server.
If you are running for the Trolls, it probably makes sense to use FGII, the product with actual C&C support. It's well-integrated with the game.
On the other hand, everyone I play with uses Maptool or Roll20. I like playing Maptool because I can write useful character macros and CKs like it because dragging and dropping stuff onto the play surface/table is quick and usually works. Because maps are infinite and easy to zoom and move around, lots of CKs will drop lots of maps of different sizes and scopes to the play area just to keep moving. Roll20 has no firewall issues to deal with (well, maybe NAT if you use the built in voice chat), and at least with some browsers drag and drop to the map library works OK.