How into Weightlifting

First: If you want to get into weightlifting, you do weightlifting.
You do not need a 'strength base'. The hard part of weightlifting is getting the technique right, start that as soon as possible.
There's no reason you can't do this at the same time as building your strength up. Build weightlifting specific strength by doing high bar/front squats, and snatch/clean pulls (not low bar squats and deadlifts), at the same time as you develop your technique.




TRAINING

Always do the more technical lifts first unless you have a good reason not to (as a beginner even if you think you have a good reason chances are it's not, so just stick with this rule for now)
A decent beginner program should have:

• Technique work (ie snatch or clean + jerk) at least two days a week
• Strength work (ie squat or pull) at least two days a week
• As a weightlifter you should always aim to be increasing your strength on squats and pulls, as this is what will determine your potential for success
• Long warmups, with no bar, empty bar then gradual adding of weight
• Dedicated time to stretching/self massage after every session
• 3-6 sessions a week
• Deload week every 2-4 weeks
• Stay inside the 3-5 rep range for technical exercises, and the 3-8 rep range for strength exercises
• Good idea to include some bodybuilding/core work too
• 8+ reps in a set
• Upper body presses/pulls, isolation work, abs, lower back...

You should have a rough idea of weights you want to hit, and total number of sets for each movement in a session. Do multiple sets on each warmup weight, only increasing weight when you're happy with your technique. 

Example training session (with rough times per section):
(weight/reps) x sets

• Dynamic warmup 10min
• Snatch 20-30min
• (20/3)x3, (40/3)x3, (50/3)x3, (55/3)x2, 60/3
• Back Squat 20-30min
• (40/5)x3, (70/5)x3, (100/5)x5
• Overhead press 15min
• 20/5, 30/5, (40/5)x3
• Shoulder bodybuilding/prehab 10min
• Abs 10min
• Cooldown/stretching/self massage 20-30min

Total training time: ~2 hours

If short on time you could just do the first 2 movements; the rest is just accessory for building general strength and helping reduce injury likelihood. But try to get it done sometimes; you can't be a good weightlifter with no muscle or strength.

A simple weekly schedule could be:

Monday		Tuesday
Snatch	~6 sets	Clean&Jerk	~6 sets
Back Squat	~5 sets	Clean Pulls	~5 sets
Thursday		Saturday
Snatch	~6 sets	Clean&Jerk	~6 sets
Sn Pulls	~5 sets	Front Squat	~5 sets

Sets here are working sets. At least the same number of sets should be done during the warmup to these. I'd suggest choosing a rough minimum weight you want to hit, and starting working sets from here. Aim to increase this minimum. If work goes well, add weight. If work goes badly, take weight off, even if going below minimum. If this happens, consider changing your minimum too. All working sets should be done with as good technique as the warm ups; if you can't do this lower the weight.
You can easily substitute in different variations instead of full snatch or clean & jerk, or change pulls to pausing at places, pulls from blocks etc...
Each session should really finish with bodybuilding/prehab/core work, then stretching/massage.

Avoid powers and be careful with hang/block work as you may well start in the wrong position. Majority of focus should be on the full lifts.

Note that a good program isn't going to make you good; you have to focus on every lift you perform. If you know something you are doing wrong and don't attempt to fix it on every rep, you aren't training right. There is no magic shortcut program which will make you strong and give you perfect technique, you have to spot your problems, try to address them in every rep and possibly do complexes/variations to allow you to focus further on the problem area.

If you cannot drop weights at your facility, you should first try very hard to find somewhere where you can. 
If that's not an option, it's still possible to lower weights under reasonable control and progress. In fact, if you can't lower the weights under some kind of reasonable control, chances are you're not in full control of it, and should be training with less weight.

MOBILITY
For mobility stretch your quads/hammies/groin/glutes/ankles (with both straight and bent leg) and do shoulder dislocates. This covers most of the important stuff. Also if you have trouble squatting the best way to fix this is just pause squats, and hold unweighted squats for long periods of time.
If mobility prevents you doing the full lifts just get down as far as you can and keep practising the lifts and working on mobility.

EATING

Slow weight gain, qualifications here

If you're really really fat, first get at least moderately lean (10-15% bodyfat or so). Then look at weightlifters at the olympics and their height and weight as a rough guide for where you should be heading. Or just pick a class or whatever you can choose. Then slowly move towards that class. Don't rush things, don't bother bulking/cutting, just slowly move towards that class. It can take 2-3 years or so, more for taller people.
Get your protein (~2g/kg bodyweight) and calories, beyond that it doesn't matter a huge amount. Calories can just be adjusted by seeing what's happening on the scale over a period of time.

TECHNIQUE

When you first start, do the pull to the 'pocket' (moment before explosion, hips in snatch, upper thigh in clean) very slowly, ensuring you are hitting the correct positions when the bar leaves the floor, when it is at the knees, and when it is at the pocket, pausing at each until you get a good feel for them. The snatch and clean image series on this blog should help give you a basic idea of the positions you want to be hitting, but do not use these as your only learning tool.
Watch world class lifters lifting lots, record yourself, post it on websites for form checks, and, most importantly, remember; if the lift looks different from how it would at 20kg lighter, you're lifting too much.
Good websites for this:
Pendlay's forum
LEDDIT
and some others.

COACHING
Having a coach is extremely useful; they will already know everything you're going to spend the next year or more researching, saving you a huge amount of time and effort, and speed up your progress huge amounts. They will also be experienced with looking for technical faults and methods of correcting them, something you can only get good at with experience.
If at all possible, get a coach. But not having one isn't going to prevent you getting very good, it will just cause lots of wasted time and mean you have to obsessively research into technique, programming etc.

LINKS
Videos
Snatch tutorial
Clean tutorial
(only watch tutorial vids by successful coaches, or maybe successful athletes)
Dynamic warmup example

Useful Websites
Catalyst Athletics - Everett's site, some nice articles and exercise videos
AllThingsGym - Blog on everything related to gyms and serious training
Ironmind - Good articles and information, also has a decent forum
Lifthard - Good articles on Chinese system, be wary of his more recent stuff (he left his Chinese coach, who doesn't really approve of much of his recent stuff)
Sportivny Press - Tonnes of excellent articles
Dynamic-eleiko - More great articles
Athletes Treating Athletes - Excellent articles on recovery
QWA Calculators - Average lift ratios, note there is often significant variation in these between good lifters
WLShoes - Weightlifting shoes reviews (yes, you really should get some shoes)
Reddit post with even more websites

Photographers
Hookgrip
Rob Macklem
Wonderlifter

Books
Everett's Olympic Weightlifting - good beginners guide to weightlifting
Takano's Weightlifting Programming - good guide on programming (Russian/Soviet approach) and other aspects of weightlifting training
Roman's Training the Weightlifter - describes the Soviet approach to training athletes

Okay, Peace out, Bye