First you need to be able to read tab and understand it. Tab is 
short for tablature. Its easy once you get the hang of it. Heres 
how standard tab is written: 

G|————————————————————————————————————————|
D|————————————————————————————————————————|
A|————————————————————————————————————————|
E|————————————————————————————————————————|

Each line is a string on the bass neck.
The letters at the beginning of the line are just the notes of 
the strings. Forget them for a moment and look at it like this:

Thinnest    |——————————————————————————————————————|
2nd thinnest |——————————————————————————————————————|
2nd thickest |——————————————————————————————————————|
Thickest    |——————————————————————————————————————|

So basically, when youre standing up with the bass round your 
neck with the strap on, the thickest string (E) is at the top and 
is usually the hardest to play. The thinnest string (G) is at 
the bottom and is the easiest to play.
There is numbers written on the tab bar and these are the frets 
you play. Bass is usually played on one string and is very rarely 
played on more than one string. If there was a 0 on and line then 
you play and open string. In other words you dont put your finger 
down on any fret. Frets are those funny metal lines on the neck 
of the bass.

G|—0———————————0———————————0————————————————————|
D|———0———————0———0———————0——————————————————————|
A|—————0———0———————0———0————————————————————————|
E|———————0———————————0——————————————————————————|

Practise that so you get the hang of playing the strings. With 
bass you can use a plectrum (pick) of you can use your fingers. 
Some people think it sounds better if you use your fingers but 
thats just their opinion. If you dont want to use your fingers 
then use a pick. Just see how fast you can play that, it might also 
help build up speed because at first it will be really hard to 
play fast. 
If there were a 1 on a line then you would put whatever finger felt 
more comfortable just in front of the first fret on the bass. 
If you put you finger on the fret then a buzzing sound might be 
made so youll need to be careful with that. 

G|—1———————————1———————————1——————————————————————|
D|———1———————1———1———————1————————————————————————|
A|—————1———1———————1———1——————————————————————————|
E|———————1———————————1————————————————————————————|

It not just numbers that appear on these lines though. Xs can 
appear on the lines. If you do find an X, then you rest your finger 
on string so its muted. You dont press down on the string and 
it doesnt matter where on the string you rest you finger. It 
would appear like this

G|——X———————————X———————————X—————————————————|
D|————X———————X———X———————X———————————————————|
A|——————X———X———————X———X—————————————————————|
E|————————X———————————X———————————————————————|

Practise that and youll soon get the hang of muted notes. 
Theres also hs and ps. The meant Hammer ons and Pull offs. 
To do a hammer on, hold a finger of a fret and strike the note or 
play an open string, and then without striking again, you put 
a finger quickly on a fret. Its difficult at first but so is everything. 

A pull off is where you put two fingers on different frets on the 
same string, and you strike the first not, and the, again without 
striking the second note, you pull your finger off, leaving 
the second finger that was on the lower fret on, and it should 
produce the same kind of sound as if youve just played that note. 
Practise and youll get the hang of it. 

G|—1h2—————————————————————1h2————————————————|
D|—————1h2—————————————1h2————————————————————|
A|—————————1h2—————1h2————————————————————————|
E|—————————————1h2————————————————————————————|

Try playing that and building up your speed the play this:

G|—2p1—————————————————————2p1——————————————————|
D|—————2p1—————————————2p1——————————————————————|
A|—————————2p1—————2p1——————————————————————————|
E|—————————————2p1——————————————————————————————|

Again practise, build up speed. It worked for me. 
Theres also harmonics. Theres many different signs for this 
though and everyone should tell you if they have used harmonics 
and what symbol they have used. I usually use a star (*). To produce 
a harmonic, place your finger over a fret and play (it works best 
with the frets 7, 9, 12 and 19). It should produce a bell kind of 
sound. If not then practise a bit more. Try playing these. 

G|———————————7*——————————9*—————————————12*—————————————19*—|
D|————————7*——————————9*————————————12*—————————————19*—————|
A|—————7*——————————9*———————————12*—————————————19*—————————|
E|——7*——————————9*——————————12*—————————————19*—————————————|

Also X's can appear on the tab line. If it does then this means 
play a mute note. That's when you just mute the string with you 
finger, not actually pushing the string down just holding your 
fingers on it. Practise this

G|———————x———————————x———————————x————|
D|—————x———x———————x———x———————x——————|
A|———x———————x———x———————x———x————————|
E|—x———————————x———————————x——————————|

And lastly, theres some slashes. / and \ mean slides. / is 
the most common and thats just slide from one note to another 
but if its just a slide then the slash will tell you weather to 
slide up or down the neck. / means slide up. e.g. from 3rd fret 
up to 12th fret. \ means down. e.g. from 12th fret to 3rd fret. 
try these

G|—3/7—————————————————————6\5———————————|
D|—————7\3—————————————1/9—————12\———————|
A|—————————7\3—————5/9—————————————3/————|
E|—————————————3/6———————————————————————|

To get better at playing and to play faster, i useually get one 
of my friends to write numbers from 1—10 on 4 different lines 
and use that as tab. When you get better you could go from 1—15 
and then 1—20. It's fun once you get into it. 
I will submit a few beginner excersizes soon.
If you find any problems, of just want 
to ask any more questions email me [email protected], 
skater—[email protected] or leave a comment. I don't bite. 
Luv yaz, Danielle xxx