At only seven days, I would do nothing at all and leave the brew sit until three weeks in the primary (minimum) before you start asking yourself "what went wrong." Most folks that assume their brew went south start fiddling around, then end up doing more harm than good. Just leave it sit...
...there could be ten reasons as to why you're getting that SG reading, none of them having anything to do with the actual SG of your brew. In order to get a good culture, you need to use a starter, use nutrients, and properly aerate (in addition to all the other things that lead to a good brew, such as proper sanitation, a good recipe, late extract editions, etc etc etc).
What type of brew is this anyway, and what was the intended starting gravity? A lot of the heavy beers I do end up at 1.020, and that's around where I want them to be, so maybe you're fine anyhow. But again, primary fermentation can take up to 2 weeks, plus 1-2 weeks of conditioning time -- so by all accounts you're jumping the gun making a call on it this early, especially considering lackadaisical pitching practices (none of which were any fault of yours, but due to the instructions that came with your kit).
In other words, put that lid back on your primary and leave it alone for another 3 weeks. Just forget about it entirely. After that time, prime & bottle, and let it sit for another 3-4 weeks. Again, forget about it entirely. Put in the fridge for a week, then sample.
During all that down time, you should think about what you can do next time to ensure a good beer. Things like proper oxygenation (preferably with an oxygenation kit), a yeast starter (preferably with flask and stir-plate), and yeast nutrient are only a few of the things that contribute to a solid culture and, subsequently, a solid brew.
Don't lose sleep over your first beer. If it's drinkable after the above fermentation and conditioning times, then you're moving in the right direction. I was fortunate in that my first brew was pretty good -- nothing close to great, but better than most garbage that's out there. It encouraged me to research techniques, buy the proper equipment, etc. Now I'm turning out some really fantastic brews. I'm sure you'll be in the same boat a few weeks/months down the road, but for now just get that basic information down. HBT is a great resource for figuring out the ropes. This place will make you a semi-pro in no time.
I am brewing an Amber Ale kit with a BG of 1.042- 1.044 and a FG of 1.010-1.012. I am in the middle of reading Charlie Papazian's " the complete joy of homebrewing" and just read a chapter about oxygen and yeast. and I think maybe i spotted some of the reason why i am stuck at the 1.020 Could not aerating my wort and rehydrating my yeast get me stuck at this reading?, Also if i take another Hydrometer reading in a few days and it is still at 1.020 would that not indicate that the fermentation has ceased?
