With little money the only thing I can recomend is get a dodgy copy of solidworks, email me if you need. Get using it, model anything you can find asemblies as well as simple items. Then create drawings of them. I moved from Autocad to solidworks just over a year ago, had a little tuition from a coleague at the time and then just practice. Got a job doing purely solidworks, it was very scary for a month, not really feeling like I could do it then suddenly you understand and it all sort of make sense. You keep learning but I am sure a few fellow singletrackers will chip in with advice where needed.
The books I used are by planchard and planchard http://www.amazon.co.uk/s/ref=pd_lpo_k2_dp_sr_sq_top?ie=UTF8&keywords=planchard%20and%20planchard%20solidworks%20book&index=blended&pf_rd_p=103612307&pf_rd_s=lpo-top-stripe&pf_rd_t=201&pf_rd_i=1428358498&pf_rd_m=A3P5ROKL5A1OLE&pf_rd_r=0C4TNKF8QJAC69S9G3HF
They are not cheap books at £35 each but I got away with 2 one basic one and one on assemblies.