Easy achievements:
Most achievements can be unlocked in Multiplayer mode. 
Achievements such as the ones for penalties, the switcheroo, 
the various ones for scoring and the giant killer 
are a lot easier if done against a human player.

Achievements: 
Accomplish the indicated achievement 
to get the corresponding number of Gamerscore points:

Bend it like a pro (15 points): Score from a free kick in a match. 
Screamer! (10 points): Score from over 30 yards out in a match. 
On the spot (5 points): Score from a penalty in a match. 
Good head on your shoulders (10 points): Score with a header in a match. 
One goal a season (10 points): Score with a defender in a match. 
Eat my chip (10 points): Score by chipping the keeper in a match. 
On yer bike! (30 points): Score with a bicycle kick. 
In off (20 points): Score off the woodwork in a match. 
Fling yourself at it (20 points): Score with a diving header in a match. 
Like on the training field (10 points): Score from a corner. 
Wing play (10 points): Score from a cross. 
What a Beauty! (5 points): Score on the volley in a match. 
Hero (10 points): Save a penalty. 
Director in the making (10 points): Upload a video to EA Sports football world. 
Last Gasp Goal (19 points): Score in the 89th minute. 
Giant Killer (15 points): Beat a five star team with a half star team. 
A Man Down (20 points): Win a game when down one man. 
Custom sixty four winner (50 points): Win a Created Tournament that starts with sixty four teams. 
One star winners (75 points): Win a Tournament that starts with sixteen teams, with a one star rated team. 
Huge investment (20 points): Buy a player in Manager Mode for 50 million of your chosen currency. 
Huge return (30 points): Sell a player in Manager Mode for 50 million of your chosen currency. 
Spending spree (20 points): Buy 50 players in your career in Manager Mode. 
The purist (100 points): Complete a Manager Mode season without simming any games. 
Provider (10 points): Perform a cross for a friend who scores from it (co-operative achievement). 
Frequent flyer (20 points): Win in every stadium. 
Real world winner (20 points): Win 5 Interactive League matches. 
Ranked winner (10 points): Win a Ranked Xbox LIVE Match. 
Manual labour (10 points): Win a match with fully manual settings (no assistance can be switched on). 
1st time out (10 points): Win an Online League match. 
Living legend (50 points): Reach legendary status for your country. 
Club god (40 points): Reach legendary status for your club. 
Additionally, there are seventeen secret achievements:

A.Bell Fever (20 points): Catch the A.Bell Fever by beating the creator or someone who already has the fever. 
The ol' switcheroo (5 points): Successfully perfom a pass that switches the play from one flank to the other. 
Time you played a match? (15 points): Score twenty goals in the arena. 
Gimme five (5 points): Score five goals in the arena. 
Optimus Chung (10 points): Win a game with adidas Live Season enabled. 
The Peterson (1 point): Play 50 hours worth of football. 
The Parolin Manoeuvre (10 points): Win a game whilst not signed in to Xbox LIVE. 
The Poon Sang (20 points): Win with 11 created players over Xbox LIVE. 
The Venhola Ice (20 points): Win a FIFA 09 Clubs Match with your club. 
Sparkly Clean (10 points): Keep a clean sheet. 
The Gipson Curse (10 points): Go into an online match after choosing your own arena player. 
Judas (10 points): Beat your favourite team with their rival. 
FIFA Fair Play (40 points): Play 5 consecutive matches without getting any cards (bookings must be enabled in the settings). 
Pictures speak a thousand words (10 points): Upload 5 screenshots to EA Sports football world. 
Duo-Hedgeidecimal (50 points): Enter a match with 20 people in a FIFA 09 Clubs Match. 
Jonzo's Lounge (60 points): Score 2,500 points and win 5 badges in a single Lounge Mode match. 
The Kwong (10 points): Score a headed goal with the shortest created player.