help! gimme some tips and opinions about my workout sequency

[brzl]

well, i workout the following exercises:
bench dips
Dumbbell Bicep Curl
Pushups - Close Tricep Position
Standing Dumbbell Reverse Curl
Dumbbell Shrug
Seated One-Arm Dumbbell Palms-Down Wrist Curl ( but turning hands 180º )
Seated Bent-Over One-Arm Dumbbell Triceps Extension
all exercises 3x15

Monday, wednesday and friday.... I give preference for work more arms, because i do other exercises too.... And i workout at home, and don`t have so many equipments...

bench, dumbbell and chin up bar ...
my characteristics are ...
1,75m 68kg and 32cm (arm, biceps, i don`t know the word exactly)
i am on 32cm a very long time... = / and i´m lean too


My objective is "gain muscles( inches )".... what do u think i should do ?
i hope u understand my english...