First-time grower. Need advice!

Have never grown my own plant before and am very interested in doing so. There are a few things I need help with, however:

-Looking to build a grow box I can put in my closet but have limited space: approx. 20" x 20" x ???".
*how high would this have to be and how many plants could I yield in it?

-I understand that there are different choices in lighting options, but what is most effective and how high must it be from the plant?

-Will one fan work and will a carbon filter eliminate the smell?

-Where can I find good seeds? I rarely find seeds in the I smoke and have heard of people buying them via the internet? Is this a legitimate option?

Any answers/suggestions/feedback are welcome!

is your closet 20" x 20" or the grow box you want to build? how high your box needs to be all depends on how tall you want your plant to be, and sufficient amount of room for the light/fixtures. with only 20" x 20", i would personally only do one plant, and TOP/FIM or LST and what not. the distance between the lights and the plant all depends on your light. for example, an HPS has to be further away than CFLs which are right up next to the plant. one fan should definitely work for that amount of space, not sure about carbon filters (never used one myself). and not quite sure about seeds either, ive been growing bagseed. hope some of this helps you and happy growing!

That would be the size of the box I plan on using. I was thinking of using the CFLs so basically how high would the box need to be for something such as this and how many/what wattage should the be? Great help, thanks for the reply

Agree with the 1 plant recommendation. I would go CFL or LED in that small of a space just due to heat concerns. The most watts you can fit in there. I would try for at least 4 or 5 feet tall. A 4" inline fan would be plenty and I wouldn't worry about the carbon filter just yet. With one plant it might not smell too much and you won't need it for a month or so anyway.

I've ordered seeds online via Attitude Seeds and I got them just fine. Popped the first 3 on 7/12 and they all sprouted so they seem to be good quality seeds so far.

One plant it is! Would 2-3 70 watt lights suffice for this space? Thanks for the seed recommendation, checking it out now.

I tried the same sort of thing mate. Was easier to just buy a grow tent that suits your closet size. I'm using http://www.ebay.com.au/itm/New-Hydroponics-Grow-Box-Grow-Tent-Grow-Room-0-8x0-45x0-8m-Indoor-Growers-/330787565561?pt=AU_Seed_Starting_Hydroponics&hash=item4d0479aff9 and it's just a wee bit to small. I'd go the next size up at 0.9m x 0.5m x 1.6m as my plant is to bushy and I ran out of hight at 800mm. But it's a one plant and has enough room to start a seedling etc. But yeah I found it easier just to buy one. I'm using clf,s ATM and getting great results. And all the bs about one plant not smelling is crap.. Mine stinks something fierce. U will need fans and filters etc. Basically stinks the house out if I leave a door open. I'm a first time grower and with research and the appropriate set up I have no doubt you will succeed.

I see I see. Smells will definitely be an issue so it's something I am planning for. Thanks for the info., I'll check the tent out!