This deck is optimized for getting out quick creatures and tokens to overwhelm the opponent.
Reasons of choosing each card (I will finish this section later)
Artifacts:
Isochron Sceptor is going to be godly. Take a look at the sceptor, and take a look at the 2 cost instants. Because you can tap this artifact for the instant's ability immediately without paying the cost, pairing this with Autumn's Veil (awesome anti-control), Dawn Charm, Druid's Deliverance (no combat damage, and populate, you can even just use it to populate each turn), and Selesyna's Charm (Token producing machine, or use it to exile creatures that your opponent controls that have greater than 5 power).
Creatures:
The Champion of L gets 1/1 for every creature that summoned under your control, and not only that creatures that have less power than the Champion cannot block the attack. Although this is a 3 drop, you won't have trouble getting more creatures out after you summon it.
The Hero of Bladehold is quite awesome, summoning more tokens everytime she attacks and as well as giving +1/0 to every other creature when you attack with her and other creatures. If you have the Champion of L out you can further increase its strength.
Lumberknot was put into the deck to be a deterrent to effects that target every creature for damage. For instance if I had weak tokens out, and an opponent plays a card that has an effect of "deal 3 damage to every creature", every token that was destroyed under this effect, can be added as a +1/1 counter to Lumberknot making it really powerful (and saving it from dying).
Mikaeus is awesome because of its strengthing effect of +1/1 to your creatures/tokens everytime a counter is removed from it, and since this is a populate deck this effect is awesome.
The Guildmage is a token producing machine as well as a population machine. And Wayfaring Temple is awesome because it will be very powerful if u summon it while having many creatures out.
Enchantments:
Beastmaster Ascension requirement for its +5/5 for all your creature's effect would be easy to accomplish as you will be able to have many tokens out which you would attack with.
Fists of Ironwood would be awesome because you had something like a powerful Lumberknot or a Wayfaring Temple out, you can equip it, and not only does it give trample but also summons 2 more 1/1 tokens (which could feed into the effect of the Champion of L making it stronger).
Growing Ranks, and Parallel Lives: EVEN MORE TOKENS, (not only feeds into the effect of Champion of L, Wayfaring Tower) but also will overwhelm your opponent.
And finally Glare of Subdual: This effect will be very useful as you will have so many tokens out, you can actually tap them to tap other monsters as you please. Implications: Death to opponent as they cannot block the incoming onslaught :D
Instants: I already described some of these cards when I talked about the artifact. However, I did not talk about the Rootknot defense. This card will be your defense against Day of Judgement, or cards that wipe the field, and not only that you can Populate after saving your tokens.
Planeswalker:
Obvious: Token producing machine, and increasing +1/+1 effect for all creatures you control.
Sorcery: MORE TOKENS