I'm a primary support who has/had the same issues with ADC. I'll let you handle those, since I'm not that great. However, if you're looking for a really great ADC, like the Riot Facebook page and get the RG Tristanna skin (champ included)... She's like the perfect adc to learn outside of the 450 IP Sivir.
For support: Runes/Masteries are INCREDIBLY champ dependent. Even as a support, I generally have to look up the runes once I start a new one. For example, thresh will go "standard" with Armor Marks, Health Seals and MR Glyphs (I forget what Quints he uses). However, Zyra does like AP and Magic Pen Runes with some armor variants for early trading. It's because supports have so many different champions to try (basically anything with hard CC or lots of soft CC) that we end up with so many different options.
Tactic wise in lane... Generally, a support will stay in line with the adc. However far the adc pushes, a support pushes. Poking is generally the job... burn the adc's single potion. Do this and poke them out of lane, your laner can dominate. Kills are optional, just get the adc out of lane. If you're playing as a kill-lane support (Leona, Thresh, Blitz), get in those side brushes. Even if you can't get picks, it will often force wards in those bushes which means early river and tri aren't warded until first back. Even then, you shouldn't push too far ahead of your adc.
If you're playing against one of those kill lanes, ward that bush. Yeah if feels like you're loosing out on vision and you are, but that's one of the tradeoffs you have to take in that match. If they get greedy and push too far, initiate a quick trade. Never trade for long enough that their adc can come forward and turn it. Poking them out so they have to use a potion is a win.
Once you go back, buy wards. If you have a main upgrade to get (generally gold gen), that comes first. Potions are generally second in a trade lane, until about 7 minutes. If you don't have wards by seven-eight minutes, you're going to die to a jungler. Warding points in bot lane are really easy early. If you're blue and pushed: Ward tri, ward river, ward Blue Buff entrance (by dragon pit). If you're red and pushed, same wards. If you're blue and still close to turret, ward dragon, ward tri and drop a ward between raptors/mid/red. Midlaners love that ward. For Purple side and near your turret, ward river, ward your blue buff entrance, and ward over blue buff wall to the intersection by mid. That almost always is enough to keep you safe. Buy pink wards, get sweeper... Late game, warding has to be learned. Generally, ward along the line where the towers are down. If your team is losing towers, ward your side tower line. If opposing team is losing towers, ward their tower line. For example, after mid outter is down, one of the best wards in the game is inbetween wolves and blue. There's five converging paths right there, but it isn't useful if the enemy is in their base because inhib turrets are falling or if your tier ones are the ones under fire.
Actually, this is completely preference: A lot of supports will, at level 9, change out their sweeper for a pink ward. Since denying vision is rather difficult if you don't see it dropped, pinks are more useful. Using three charges of the greater vision totem and you're already gold efficient... trust me, you WILL use those charges. In super late games where you have full item builds, place one last pink (generally by baron), switch that to greater stealth totem, sell
and get another item. That almost never happens though. But wards are probably the signle most intricate job a support has, since it is micromanaging for the rest of the team. It is one hell of a thankless job, but in games between two close skill teams, the game is essentially won by this. (That's why it's so thankless... no one thanks the vision for their 'LCS plays' they make).
So now that warding is covered... Roaming. Roams are one of the things ADCs hate but supports and midlaners love. If you go warding up the river, you can generally ping MIA and a destination indicator. Ward up, sweep the mid river bush, and go in if the laner is within distance of your spell. This really only works for kill lane/poke lane supports (Thresh, Annie, Morg, Blitz are known to be the huge roaming threats), so don't try this with Soraka or Taric.
When roaming, just remember that vision is first. If you get counter ganked when you come mid, it's 'your fault' regardless of mid lane's prior lack of wards or the fact that it might've been inevitable. Also, you're away from the ADC. You are the TEAM support, but you do have to protect the adc early. If he screws you over and pushes the lane hard, you kinda have to head back unless vision is impeccable. If you're purple team, you want to gank from the path closes to the opponent mid's tower unless they're really shoved. Again, this requires you ward that space. If blue, gank river... that stupid intersection is a surprising death trap and the jungler crosses there a lot when handing blue off.
In teamfights, know your role. If you're a kill lane support, you probably initiate for the team. Being close to the front or the front itself is where you'll most often find yourself. If you're a sustain support, you'll be peeling for the team unless you're thresh, in which case this is your job still. The only inbetween are supports like Morgana, Lux or Sona who are 'poke supports' by nature. Position for them is generally right behind the jungler until you plan to ult. Afterwards, they generally fall back towards mage positioning (especially since they have shields of sorts).
Lastly, probably the most important pre-req of a support: Learn to hit skillshots. Almost every support has their main calling card being a skillshot. Janna, Nami, Thresh, Blitz, Morg, Zilean, Zyra all rely on their skillshot to do anything for the team.