Ah Grasshopper. Using tab and chord sheets are good for getting some songs to play under your belt but if you want to improve and be able to do away with those silly chord books (not song books) there is a magic bullet. It is the CAGED system of guitar chords. There was one particularly good lesson on the web about using this in a chord melody format...the chord melody portion gets deep so if you find the lesson just ignore that part. there are several others out there as well
What you need is knowledge of the basic cowboy chord forms (ie the open positions). You also need to learn how to spell chords based on scale intervals. knowing scales is also good but not really needed at this point. the lessons will show you how to link the chords up and down the neck using bars and partial bars. using the spellings you get 135 as a recipie for a major chord, 1357 for a maj 7th, 135b7 for a dom 7th, 1b35 for a minor etc. there are a million lessons with chord spellings out there. (b=flat, #=sharp))
what the hell is 135 you ask. take a major scale (cdefgabc for example) and number from start to finish twice. Why twice you ask? because the d in the C scale used as an example acts as a 2nd but also as a 9th which is how you will tend to see it in a chord. Likewise a 6th and a 13th, a 4th and an 11th are the same respectively. you also need to remember that a major scale is wwhwwwh with w= whole step (2 frets) and h = half step (one fret). THe cool thing about this system is that you are working with forms and numbers and can skate by without the note names for a long time and by shifting forms up and down the neck you get to change keys but only have to track the same ole forms.
the important note to identify in each chord form to begin with is the 1, or the tonic...i.e. the note that gives the chord it's name. from that the 7th is a half step down same string (all figured from the one), the b7th is a whole step down same string. The 4th is same fret one string up ..up being 6th string to 5th for instance(need to adapt this by 1/2 step between 3rd and 2nd strings). 5th is one string up and one fret up. the third is one string up 1/2 step down. a b3rd is one string up and a whole step down. and octive is two strings up and a whole step up. the octave is just a repeated 1 so the whole process starts over. Using wwhwwwh you can fill in the blanks when a chord tone other than those comes up. another good one to remeber is that the 5th is also one string down same fret (ie if the 1 of interest is a d on the 5th fret 5th string the 5 of that scale (and appropriate chords) is on the 5th fret 6th string).
note: scales are notes arranged linearly while chords are just scale tones stacked vertically (generally in intervals a 3rd apart)
what you get out of this is the ability to form any chord you want anywhere on the neck by building it on the fly rather than memorizing a million chord forms.
For the advanced guys: this approach opened my eyes wider and faster than 25 yrs of playing...if only i learned it ealier. if you know the 5 major scale patterns and how the link up you will quickly see how all the chord forms relate to one or more of the scales. this alows visualization of the scales and chords over the entire neck. You also can move into combining chord tones and scales in soloing and chord melody work in a much more natural way. Using the chord form as a base gets you into playing the correct modes (all a mode is is the appropriate major scale that, when started at the tonic of interest and evauated in stacked 3rds, gives you the chord of interest). as you proceeed on this coarse and start thinking about chord substitutions you will notice that parts of some chords are identicle to parts of other chords with the same form, and notes but with different names. That can lead you to substituting scales as well but that is a way different animal i haven't mastered enough to talk about much.
Waaaay too much information is what i bet you are saying at this point. Ya it is. actually it is the key to understanding the neck and incorporating theory with minimal pain. as a start at least learn the cowboy chords in open position and relate the 1, 3, b3. 7 and b7. That alone will give you a ton of chords. Basic bar chords result in moving the E shape chord (tonic on the 6th string) and the A shape chords (tonic on the 5th string) up and down the neck. Learn to manipulate just those two forms and you'll be miles away from a lot of players. then when you see the B7b5b9 chord it won't scare you ...just build it.