Good practice routine suggestions

I must say that my level of musicianship isnt all that great, but I'll try and help anyway

Warm up
For this I use a chromatic exercise, playing one finger per fret, starting on the open E, and moving up one semitone each time. This helps technique too.

Scales
I'd then move onto some scales. What I do is pick one scale at random, and play it up and down the neck in all the different positions. Play it until you are goddam sick of it. If you know the modes of that scale, then do the same for those as well. Once you've played the scale, practice firstly grooving on it, then making melodies with it. Use a new scale each practice.

Jazz
I don't know how much you are into jazz, but learning and playing jazz helps you no end. What I'd recommend is getting a teacher if you don't already have one, who can help you with the theory and improvisational side, but failing that books can be a useful substitute. I'd recommend Jazz Bass by Ed Friedland as a starter, and The Jazz Theory Book by Mark Levine as the definitive theory book. I'd also recomment getting a real book, and once you have started off in jazz, practice walking and soloing through some changes.

Ear training
To help your ear training, I'd firstly recommend a cheap keyboard/piano. With this you can start to learn to hear different chords, then practice playing over the chords and seeing what sound good over what. I'd also recomment transcribing, not just bass lines but other solos and melodies. This will help your ear and also help making your own lines.

Playing along to records
If you have a few favourite songs/albums that you know the basslines too, practice playing along to the records. This helps youre time and helps to give you the feel of playing in a band situation. You mentioned The Beatles, playing along the their records would be ideal.

With all of this I can't stress enough the need for a metronome, but other than that, enjoy it

 

This falls under Ear training.


Sight-Singing.

get some pieces of music, doesn't matter really what it is, bass clef or treble, which ever, you could do it on your own, but you may make more progress with a friend.

basically, give yourself the first note, of the whole piece, or just one phrase, or a couple measures(as long as you want)

give yourself the first note, and then try and sing it, out loud, based on that note.

It is unblievably helpful in improving your ear.

 

I used to do the same thing, kindablue. I would sit down and have the idea that I would spend 'x' amount of time on this, then 'x' amount of time on that, and on, and on. Not much would sink in. Now when I practice, I sit down with one subject in mind, and work on it slowly until I feel that I have fully comprehended the subject at hand (i.e., I can do it in my sleep, or so to say.) Then, and only then, will I move on. I picked this up from the book, Effortless Mastery, by Kenny Werner - a great book.

Also, you may want to check out these search results. Lots of useful info as far as what should be practiced.

 

Practice Routines