A good note for beginners is that in most cases in standard you're going to want to be running around 23 ~ 26 lands. People in tournaments typically run closer to 26 to prevent having to mulligan and nearly guaranteeing they play a land every turn. Of course, there's also a red, super fast and aggressive deck that runs about 18 ~ 21 lands, but every creature in that deck requires 1 to 2 mountains to play. The Simic devotion deck, which is really awesome, is a good place for you to start and get some ideas.

Check out this link for the Simic devotion deck:

http://magic.tcgplayer.com/db/article.asp?ID=11466

He's playing a mana-dependent and creature heavy deck (like yours) but has tons of insane ramp in Nykthos, Shrine to Nyx and other mana-dorks so he can afford to run only 24 lands.

Another good thing to note is your curve, or that "Converted mana cost" bar graph to the right of your deck. You want to generate a smooth graph. Typically trending upwards from 1 ~ 2 and spiking at 3 or 4 and declining from 5 on wards. Of course this is all depending on how aggressive you play and how powerful your spells are (Some modern decks spike at 1/2 and drop off at 3 for example). This essentially allows you to judge how smoothly your deck will play and that you will always have a spell to cast each turn. AND, a curve peaking around 3 ~ 4 usually means that you (usually) wont late-game top-deck a horrible card (for example pulling a Sylvan Caryatid on turn 6 when you have 12 mana already available to you).

A great example of the a smooth mana curve is the Mono black devotion deck. I have my version of the mono black deck on here and you can check out the curve as a reference. New MonoBlack.

So try applying those concepts to your deck and see what you can come up with. Once you do that I'll be around to help guide you some more. Also, I highly recommend watching those videos on that TCGPlayer link of the UG Devotion deck.

I would definitely recommend more card advantage, which is vital against Mono Black, WU and Esper control. Fathom Mage is too slow and unreliable. More Garruks, Prime Speaker Zegana , and Jace, Architect of Thought are all solid options. I also really like Simic Charm for Hexproofing here, and Cyclonic Rift since you can easily Overload it. You could probably do without Deadly Recluse and Seek the Horizon. Bumping the land count up to like 22 would also be a good idea.

Check out my GU Devotion deck- My Prophet, Your Loss (Top 4 FNM)

Thanks for the tips guys. The deck is mostly made of cards i had available to use cause I dont have 80 to sink into just planes walkers lol. I wanted to try and make a deck purely of creatures, but its not working out too well. Ill rework the mana and try and get a decent curve going. And thanks vincentgalbo those videos are pretty helpful.